Crossbows - Everything about Building, Modding, and Using your Crossbow Gear

Latest topics

» Chinese crossbow with auxiliary string?
by stm2010 Today at 9:48 am

» 15th century saxon prods
by Geezer Today at 7:34 am

» Yet another one
by jocky Yesterday at 7:09 am

» Crusader crossbow
by c sitas Thu Jun 22, 2017 9:41 pm

» Whamo showed up, prod replacement ideas
by kenh Mon Jun 19, 2017 4:25 pm

» Renaissance Sporting crossbow
by tony a Mon Jun 19, 2017 2:10 am

» loose laminate issues
by c sitas Sun Jun 18, 2017 8:42 am

» Of Bows and Torsion Engines
by c sitas Fri Jun 16, 2017 2:55 pm

» My second crossbow
by Daniel Levesque Fri Jun 16, 2017 10:48 am

» Need to locate Windlass Crossbow, pre 1600, in Rome, Venice, or Florence
by 8fingers Tue Jun 13, 2017 11:24 pm

» Crossbow Projectiles
by Geezer Tue Jun 13, 2017 8:10 pm

» Greetings!
by OnlyHuman Mon Jun 12, 2017 7:40 am

» Anyone know what this is?
by Yuki23emma Sun Jun 11, 2017 2:54 pm

» Prod specs
by Onager Lovac Mon Jun 05, 2017 4:25 pm

» Finished Crossbow
by kenh Sat Jun 03, 2017 8:34 pm

» The Arbalist Guild - Around the World
by Turnigy Fri Jun 02, 2017 1:25 pm

» Reverse draw "compound" build
by Turnigy Fri Jun 02, 2017 1:20 pm

» Casting Resource
by White Oak Wed May 31, 2017 2:28 am

» The Road so far......
by White Oak Mon May 29, 2017 7:17 am

» GLOSSARY OF TERMS
by Onager Lovac Wed May 24, 2017 6:41 pm

» Hello from Maine
by White Oak Sun May 21, 2017 11:06 pm

» Leonardo Da Vinci string with suport-rolls
by Oppenheimer Tue May 16, 2017 11:40 am

» Compact repeating compound project
by Phil Abrahams Mon May 08, 2017 2:10 pm

» Trying to reduce the power stroke in my next project
by octavioaugusto.oliveira Thu Apr 27, 2017 1:27 pm

» Its good to be back!!
by Juan galeano Tue Apr 25, 2017 9:31 am


    Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Share
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Thu Dec 24, 2009 2:32 am

    ~Shoulder Stock Anatomy~

    First of all...I'm not a pro...just a guy who got his nerve up to try his hand at making a shoulder stock and it turned out decent enough to be at least slightly proud of.

    This subject has bothered us all...So let us talk about building a "Custom fit stock" or at least some thing that looks and feels like one.

    Just to clean up all the mess in the future...crossbows came after bows...rifles came after crossbows, but it was the crossbow that borrowed the Rifle stock from the rifle and not the other way around. In fact the stock was made separately from the rest of the weapon by a specialist stock maker.

    Here is some nice info I ripped from around the net...mostly from wikipedia thou Embarassed :

    Stock

    A stock, also known as a buttstock or shoulder stock, is a part of a rifle or other firearm, which the barrel and firing mechanism are attached to, that is held against one's shoulder when firing the gun. Stocks are also found on crossbows though a crossbow stock is more properly referred to as a tiller. The stock provides a means for the shooter to firmly support the device and easily aim it. The stock also transmits recoil into the shooter's body.


    The anatomy of a gunstock. 1) butt, 2) forend, 3) comb, 4) heel, 5) toe, 6) grip, 7) thumbhole


    History and etymology

    The term stock in reference to firearms dates to 1571 is derived from the Germanic word stoc, meaning tree trunk, referring to the wooden nature of the gunstock.

    Early hand cannons used a simple stick fitted into a socket in the breech end to provide a handle. The modern gunstock shape began to evolve with the introduction of the arquebus, a matchlock with a longer barrel and an actual lock mechanism, unlike the hand-applied match of the hand cannon. Firing a hand cannon requires careful application of the match while simultaneously aiming; the use of a matchlock handles the application of the slow match, freeing up a hand for support. With both hands available to aim, the arquebus could be braced with the shoulder, giving rise to the basic gunstock shape that has survived for over 500 years. This greatly improved the accuracy of the arquebus, to a level that would not be surpassed until the advent of rifled barrels.

    Ironically, the stocks of muskets introduced during the European colonization of the Americas were repurposed as hand-to-hand war clubs by Native Americans (Watch "The Last of the Mohicans" Wink ) and First Nations when fragile accessories were damaged or scarce ammunition exhausted. Techniques for gunstock hand weapons are being revived by martial arts such as Okichitaw.


    An early hand cannon, or gonne, supported by a simple stock

    Anatomy of a gunstock

    A gunstock is broadly divided into two parts (see above). The rear portion is the butt (1) and front portion is the fore-end (2). The butt is further divided into the comb (3), heel (4), toe (5), and grip (6). The stock pictured is a thumbhole (7) style.

    Styles and features of stocks

    The most basic breakdown of stock types is into one-piece and two piece stocks. A one piece stock is a single unit from butt to fore-end, such as that commonly found on bolt action rifles. Two piece stocks use a separate piece for the butt and fore-end, such as that commonly found on break open shotguns, and lever-action rifles and shotguns. Traditionally, two piece stocks were easier to make, since finding a wood blank suitable for a long one piece stock is harder than finding short blanks for a two piece stock.


    Different styles of gunstock grips

    The grip area is one that varies widely. A straight grip stock (A) proceeds smoothly from toe to the trigger, giving a nearly horizontal angle for the trigger hand, while a full pistol grip stock (E) contains a separate piece for the grip, providing a near vertical angle for the trigger hand, and is commonly found on modern military rifles, such as the ubiquitous AK-47 family of assault rifles. The semi-pistol grip (B) stock is perhaps the most common sporting stock, with a steeper angle cut into the stock to provide a more diagonal angle for the trigger hand. Modern target style stocks have moved towards a fuller, more vertical pistol grip, though built into the stock rather than made as a separate piece, and may be considered pistol grip stocks. Anschütz stocks (C), for example, use a nearly vertical grip, and many thumbhole style stocks (D) are similar to full pistol grips in shape.


    M4 carbine with sliding stock and pistol grip
    Butt hook on SPAS-12

    Sliding or folding stocks are often seen on military-grade arms. A butt hook, which is an attachment to the butt of the gun that is put under the shooter's arm to prevent the rifle from pivoting forward from the weight of the barrel is sometimes used in competitive rifle shooting. These stocks are also used on combat shotguns like the Franchi SPAS-12 to allow the stock to collapse when not in use.


    This beauty is the work of Crossbow Master Craftsman - Robin Allen
    ( www.thecrossbowmansden.com )

    These hooks actually feel quite comfortable, even on a really front heavy crossbow...probably the reason why a version of such is practically always used on the match target crossbows....those things weigh a as much as rail!!!


    Variations in gunstock combs

    The comb is another area of wide variation. Since the comb must support the shooter's cheek at a height suitable for use with the sights, high sights such as telescopic sights require higher combs. The Monte Carlo comb (B) is commonly found on stocks designed for use with scopes, and features an elevated comb to lift the cheek higher, while keeping the heel of the stock low. A cheekpiece (C) is a raised section on the side of the stock, which provides support for the shooter's cheek. There is some confusion between these terms, as the features are often combined, with the raised rollover cheekpiece (D) extending to the top of the stock to form a high Monte Carlo comb.

    Stock measurements

    Stock measurement is especially important with shotguns, where the typical front-bead-only sight requires a consistent positioning of the shooter's eye over the center of the barrel for good accuracy. When having a stock custom built or bent to fit, there are a number of measurements that are important.[8][14]

    * Length of pull, the length measured from the butt of the stock to the trigger
    * Drop at heel, the distance from the line of sight to the heel of the butt
    * Drop at comb, the distance from the line of sight to the comb
    * Cast off, the distance from the center of the butt to the center of the barrel, to the right side as seen from the rear
    * Cast on, the distance from the center of the butt to the center of the barrel, to the left side as seen from the rear
    * Pitch, the angle of the butt of the stock, determined by a line from heel to toe.

    Bill Hanus Birdguns wrote:As Don Zutz observes in Shotgunning Trends in Transition: "If one carefully breaks down the self-taught style of most American bird hunters, including that of many today, he will note that it is a slow, jerky, two-part move with 1) the gun first being brought solidly to the shoulder and the head wiggled into place before 2) the swing is started after the flying mark."

    When the "slow, jerky, two-part move" is made on targets offering small windows of opportunity (grouse, woodcock, piney woods quail and sporting clays for example), the target is gone. Worse, many right-handed shooters with dominant right eyes will shoot a cast-neutral, straight-stocked gun high and to the left. That's because when the head is tilted to find the plane of sight, the cheek pushes the stock to the right and down. Movement away from the target is increased by chubby-cheeked shooters and thick-combed shotguns. Consistently missing birds that flush to the right confirms this difficulty. Left-handed shooters tend to push the butt of the stock in the opposite direction, so they miss birds flushing to the left.

    A small amount of cast-off or "advantage right" at the butt usually solves the high and to the left problem right-handed shooters experience. Cast-on or "advantage left" does the same for left-handed shooters. The most important practical benefit of cast-off for a right-handed shooter with a dominant right eye (and for a left-handed shooter with a dominant left eye) is that it allows him to keep his focus on the target without having to look at his gun.

    Accuracy considerations
    Main article: Accurizing

    In addition to ergonomic issues, the stock can also have a significant impact on the accuracy of the rifle. The key factors are:

    * A secure fit between the stock and action, so that the rifle does not shift under recoil
    * A stable material, that does not suffer from changes in shape with temperature, humidity, or other environmental conditions to a degree that could adversely impact accuracy

    A well designed and well built wooden stock can provide the secure, stable base needed for an accurate rifle, but the properties of wood make it more difficult than more stable synthetic materials. Wood is still a top choice for aesthetic reasons, however, and solutions such as bedding provide the stability of a synthetic with the aesthetics of wood.

    Construction

    Traditionally, stocks are made from wood, generally a durable hardwood such as walnut. Wood is, however, a poor choice from a functional standpoint, as it tends to absorb water and change its shape, and this can cause serious issues with accuracy. Modern stocks are made from more stable materials, such as thermoplastics and composite materials, such as fiberglass, kevlar, and carbon fiber composites. A growing option is the laminated wood stock, consisting of many thin layers of wood bonded together at high pressures with epoxy, resulting in a dense, stable composite.

    Folding, collapsible, or removable stocks tend to be made from a mix of steel or alloy for strength and locking mechanisms, and wood or plastics for shape. Stocks for bullpup rifles must take into account the dimensions of the rifle's action, as well as ergonomic issues such as ejection.

    Wood stocks

    While walnut is the favored gunstock wood, many other woods are used, including maple, myrtle, birch, and mesquite. Due to the natural properties and variability in woods, stocks made from solid wood must take into account these properties. The grain of the wood determines the strength, and the grain should flow through the wrist of the stock and out the toe; having the grain perpendicular to these areas weakens the stock considerably.

    In addition to the type of wood, how it is treated can have a significant impact on its properties. Wood for gunstocks should be slowly dried, to prevent grain collapse and splitting, and also to preserve the natural color of the wood; custom stockmakers will buy blanks that have been dried two to three years and then dry it for several additional years before working it into a stock. Careful selection can yield distinctive and attractive features, such as crotch figure, feathering, fiddleback, and burl, which can significantly add to the desirability of a stock. While a basic, straight grained blank suitable for a utilitarian stock might sell for US$20, an exhibition grade blank with superb figure could fetch in the range of US$2000. Blanks for one piece stocks are more expensive than blanks for two piece stocks, due to the greater difficulty in finding the longer blanks with desirable figure. Two piece stocks are ideally made from a single blank, so that the wood in both parts shows similar color and figure.

    Injection molded synthetic

    While setup costs are high, once ready to produce, injection molding produces stocks for less than the cost of the cheapest wood stocks. Every stock is virtually identical in dimension, and requires no bedding, inletting, or finishing. The downsides are a lack of rigidity and thermal stability, which are side effects of the thermoplastic materials used for injection molding.

    Hand-laid composite stocks

    A hand laid composite stock, out of materials such as fiberglass, kevlar, and/or graphite cloth, saturated in an appropriate binder, into a mold. The resulting stock is stronger and more stable than an injection molded stock. It can also be as little as half the weight of an injection molded stock. Inletting and bedding can be accomplished by molding in as part of the manufacturing process, machining in the inletting after the stock is finished, molding directly to the action as a separate process, or through the use of a machined metal component molded in place during manufacture. Finish is provided by a layer of gel coat applied to the mold before the cloth is laid up.

    Laminated wood

    Laminated wood consists of two or more layers of wood, impregnated with glue and attached permanently to each other. The combination of the two pieces of wood, if laid out correctly, results in the separate pieces moderating the effects of changes in temperature and humidity. Modern laminates consist of 1/16 inch (1.6 mm) thick sheets of wood, usually birch, which are impregnated with epoxy, laid with alternating grain directions, and cured at high temperatures and pressures. The resulting composite material is far stronger than the original wood, free from internal defects, and nearly immune to warping from heat or moisture. Typically, each layer of the laminate is dyed before laminating, often with alternating colors, which provides a pattern similar to wood grain when cut into shape, and with bright, contrasting colors, the results can be very striking. The disadvantage of laminate stocks is that the density, with laminates weighing about 4 to 5 ounces (110 to 140 g) more than walnut for a typical stock.

    While wood laminates have been available for many years on the custom market (and, in subdued form, in some military rifles), in 1987 Rutland Plywood, a maker of wood laminates, convinced Sturm, Ruger, Savage Arms, and U.S. Repeating Arms Company (Winchester) to display some laminate stocks on their rifles in a green, brown and black pattern (often called camo). The response was overwhelming, and that marked the beginning of laminated stocks on production rifles.


    Last edited by Ivo on Sat Sep 04, 2010 11:25 pm; edited 2 times in total
    avatar
    Regerald
    Master Crossbowyer
    Master Crossbowyer

    Posts : 67
    Join date : 2009-11-30
    Age : 32
    Location : Finland

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Regerald on Wed Mar 10, 2010 3:07 pm

    Asking for help.
    Does anyone have an accurate drawings of a standard shotgun-like stock (type B), with all dimensions? Models that I've done do not satisfy me, do not feel very comfortable.. I know that I could go to the gun shop and simply measure several stocks, but this will look little bit suspicious Smile
    And also, if anyone has a drawings (with dimensions) of Napoleon-age crossbow stocks, I would be pleased to see them.
    avatar
    Basilisk120
    Moderator
    Moderator

    Posts : 548
    Join date : 2010-03-01
    Age : 38
    Location : Arizona

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Basilisk120 on Wed Mar 10, 2010 9:47 pm

    I am trying to find plans for a rifle or shotgun stock. no luck yet.

    But quick measuring of some of my guns. (Sorry to borrow your picture Ivo )


    The X length measure at the short end 8.5 in and at the long end 10.75 in on the long, averaging about 10.375 inches. I think I should have measured to the trigger.

    http://members.aye.net/~bspen/fit.html Goes into more detail about stock, repeats a lot of what Ivo said but has some numbers in it.

    http://www.scribd.com/doc/3601874/Mod-2-Gun-Stocks - Online book detailing stock making. short on numbers but long on lots of other details

    Most of the plans seem to be about the wood working and seem to imply that the builder has a gun to copy from. Can always leave the stock on the large size and remove material as needed.
    avatar
    Regerald
    Master Crossbowyer
    Master Crossbowyer

    Posts : 67
    Join date : 2009-11-30
    Age : 32
    Location : Finland

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Regerald on Fri Mar 12, 2010 5:43 am

    Thank you, basilisk120
    Model that I've done at first have "X" length about 8.5 inch (it's designed to be compact). Maybe, I just have extraordinary long arms because second model with X about 10.5 inch (26cm) feels much better.
    And also your links provide useful information about the theory around stocks..
    avatar
    Basilisk120
    Moderator
    Moderator

    Posts : 548
    Join date : 2010-03-01
    Age : 38
    Location : Arizona

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Basilisk120 on Fri Mar 12, 2010 9:02 pm

    One thing that works for me was that a long stock isn't as cumbersome as a long barrel on a gun. In fact a short stock can be quite awkward. One of my favorite brush guns has a longer stock and a short barrel - makes it swing quite nice.

    Glad those links were helpful
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Thu Apr 29, 2010 1:50 am

    Ivo wrote:My theory is:

    A certain stock anatomy trick, whether carved in
    the stock from beginning or artificially created with addition of pillow
    like grip anatomy located tight under the trigger finger...in theory I
    believed that this would change the angle in which the finger engages
    the trigger hook....ever hear of anything like this?

    Moving this conversation here...this picture is what got me thinking.




    As you can see right under the trigger finger is a cushion like object which I theorized about having some interesting effect on finger to trigger relation. Does anyone have any information on this little detail?




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Pavise
    Dear Friend, You will be Greatly Missed.
    Dear Friend, You will be Greatly Missed.

    Posts : 128
    Join date : 2010-02-07

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Pavise on Thu Apr 29, 2010 1:54 pm

    Ivo,

    I lightened the picture and can see what looks like two pieces of elastomeric material incorporated with the pistol type grip on that crossbow. This rubbery substance is often used on various handguns. Not only does the material mitigate felt recoil but also provides a certain amount of memory that makes each purchase of the weapon similar, and thus more consistent accuracy can be achieved. The subject crossbow will not deliver recoil as we know it with firearms but consistency of grip is important in crossbow target competition and this may be the reason for them on this example. Otherwise they may have been attached simply to make the grip more fitting to a larger hand than that stock was originally made for.

    Those of us who have made thumb-hole type grips know how tricky it can be to get the many curves just right and a softer grip covering material would undoubtedly make such finite details less important. Smooth-On has some interesting products that might be worth testing to this end. www.smooth-on.com


    Pavise
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Sun May 02, 2010 3:37 am

    Ahhh, so that's what it was. I was sure on my way to inventing the
    bicycle then. Smooth-On is a pretty big place with lots of cool things to
    choose from...did you have anything specific in mind?

    I've
    worked with some two part silicones that could be molded by hand, but I
    was never really satisfied with their strength and only used them for
    making molds...I mean some were more flexible than others, but still had
    a slightly grainy structure that would crack when flexed...really would
    like to find the stuff you could mold to your hand, finish with some
    sand paper and not worry much about it cracking.

    PS: I'm almost done translating an interesting stock making article...prepare!




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Sun May 02, 2010 11:24 pm

    Here are the promised goodies to add more on the subject of stock making (and perhaps I should have done this in the beginning) is this little diagram, but held out as I haven't really sat down to fully explore it - Yeh, I'm still playing with foam blocks and the hot wire foam cutter .



    I'm going to try and revive the diagram as well as translate it along with a part of this article. The automatic translator isn't eating up some of the terminology, so I hope to get close enough to the understandable (maybe even correct ) stock making terms. If I do get something wrong... PLEASE don't go by letting this mistake settle in as a correct term.

    Here we go...


    And here is the translation of the accompanying article (original here>>>Link)

    Russian to English translation

    Fig. 1. Determination of the shooter's dimensions.



    A -Basic dimensions of the shooter:



    Spoiler:
    * L - length of the arms
    bend at the elbow to the middle of the first phalanx (nail joint) and
    the index finger (measurement is made in the clothes that will be used for hunting);

    * Hp - is the height of the
    pupil of the clavicle;

    * Bc - the width of the chest between the armpits.

    B - Dimension of the stock's cast-off:



    Spoiler:
    * Oh - Offset of the heel;

    * Ot - Offset of the toe (Dimensions Oh and Ot depend on the width of the chest and face of the shooter)


    C - Main dimensions of
    the stock:



    Spoiler:
    * Lh - the length of the stock from the
    front trigger to the heel of the butt;

    * Lm
    - the length of the stock
    from the front trigger to the
    middle of the butt;

    * Lt - the length
    of the stock
    from the front trigger to the toe of the butt;

    * a - length offset to the comb at the thumb
    cut;

    * b - length offset to the the
    heel of the butt (size of a and b depend on the length
    of
    neck and hands of the shooter)

    Stock Dimensions


    The stock that is too long will prevent the shooter from quickly shouldering the weapon, too short - the shooter feels more recoil because of
    the gap between the butt of the stock and the shooter's shoulder. Method for determining
    the size of the stock is shown in Figure 1. The length of the stock is
    determined by measuring from the front trigger to various
    points on the butt of the stock. The most common length of
    the stock from front trigger to the heel of the butt (Lh) 360-365 mm, to the toe of the butt (Lt) 368-372 mm, to a point on the plane of the butt,
    located 1/4 way down from the heel of the stock (L1...strangely it isn't marked on the diagram ) 356 -
    360 mm. The size of a = 40-45 mm, the size of b = 55-60 mm. The stock of this size enables the hunter to shoot practically without tilting his head.[>>>Keep in mind! The above dimensions are for "Gun Stocks", we are making "Crossbow Stocks"...Might be a an important factor to consider "depending on the design"]

    Each hunter must have twoguns with different stocks, or two stocks for one gun, or what might prove most rational - Interchangeable recoil pad thickness. In the summer for light, thin clothing requires a thick recoil pad, such as a shock absorber, ie longer stock.... in the winter for warm clothing - a thin back plate, ie shorter stock.



    Determining the size of
    the stock for the shooter's body type.

    To do this, there are several ways.


    1. Using the fitting/adjustable stock.

    The use of fitting/adjustable stock is the most simple and reliable way. These stocks should be in every weapon shop,the arms companies involved in manufacturing rifles for individual orders. However, there are very few for sale(I guess we make our own then).


    2. Use of tables

    This method consists of measurements of several physical parameters of the shooter (the length of the forearm, the height of the pupil over the clavicle, the width of the chest between the armpits) and determining the size of the stock from them with the help of special tables.



    First, measure the length of the forearm from bend at the elbow to the middle of the first phalanx (nail joint) and the index finger when the forearm with the shoulder of a right angle and finger, palm and forearm will be in a straight line. This measurement will determine the length of the stock from front trigger to the middle of the butt. Clothing must enact winter, summer, and autumn, with the difference in sizes up to 2 cm.


    It is believed that for hunting it is better to have a shorter stock rather than longer one, when shooting snapshot this stock has less chance to catch on the clothes and will have more chance to shoulder correctly. Distance from front trigger to the heel are usually made 5-15 mm longer than the distance to the middle of the butt, and the distance to toe - from 0 to ± 15 mm, depending on the size/fullness of the pectoral muscle and the preferred use for the gun(vertical/horizontal shooting), ie, for shooting at a high flying targets, or moving ground targets. In the first case(flying targets-vertical shooting), the length of the stock to the toe of the butt should be longer, and the second(ground targets-horizontal shooting) - should be shorter.



    Then measure the height of the pupil over the clavicle to determine the vertical limb of the stock and, finally, the width of the chest between the armpits. This size is necessary to determine the offset (cast-off) of the butt to the shoulder. The required size of the box is determined by the table (Table 1).



    Determine the dimensions of the stock using the table, you might need to compare them with those of your existing stock and make the necessary corrections (for more info on that - read on).



    When using these tables you should remember that they are NOT universal. Thus, if two people of the same height and physique are offered a gun stock, carefully selected for them using the tables, the result may be surprising: for some, the gun would be ideal in shouldering, and for others - totally uncomfortable. This is explained by the fact that people of equal stature and growth have different posture, they walk, turn, bend over, bend their head, raise their gun slightly different. And it turns out that the same for the growth and stature people often call for guns of different stock. Therefore, the tables can be and should be used, but only as a rough reference material, so do not be surprised if it turns out that the stock made according to the table,suddenly appears uncomfortable. Of course, a little getting used to, changing the position of the hand holding the fore-end, you can quickly get used to the rifle, which you do not quite fit.


    Forearm length(L), см

    Length of the stock to the middle of the butt(Lm), см

    Height of the pupil from the clavicle(Hp), см

    Length offset to the comb/heel, мм

    Width of the chest between the armpits(Bc), см

    Stock offset at the butt(Cast-off), мм


    to comb(a)


    to heel(b)


    at the heel(Oh)


    at the toe(Ot)
    4238-402342-4466-7050-52186
    4137-392241-4365-6948-49175. 6
    4036-382140-4164-6846-47165
    3935-372039-4063-6544-451545
    3834-361937-3860-6242-43144
    3733-351835-3658-5940-411235
    3632-341734-3557-5838-39103
    3531-331633-3456-5736-3782, 5
    3430-321532-3355-5634-3562
    3329-311431-3253-5432-33415




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Mon May 03, 2010 12:10 am

    That was fun ...thou I didn't do the whole thing (Google translation >>>Here)...the rest of the article lightly covers cutting out and shaping of the stock as well as mentions a few wood finishes, but we'll get to that in more detail later I'm sure.



    From time to time I sit down in my reading chair with a copy of Roy F. Dunlap's - "GUNSMITHING" book and before beginning another chapter I peek into the section on Stock Making...treasure box of info on the subject, so there is much more to come!




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Pavise
    Dear Friend, You will be Greatly Missed.
    Dear Friend, You will be Greatly Missed.

    Posts : 128
    Join date : 2010-02-07

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Pavise on Mon May 03, 2010 10:50 am

    I'm sorry, but are we proposing to build stocks for crossbows or shoulder held guns? The two, whilst often appearing the same, are vastly different when examined closely. And I hate to harp on about it, but Robin Allen has long provided sound guidance on most all issues when it comes to making a functional crossbow, be it for target or for hunting. However it seems as though we are attempting to reinvent the proverbial wheel at times, when it is not necessary. The crossbow does not deliver recoil when shot, and in fact the opposite occurs as the mass of the limbs move forwards (notwithstanding some modern styles) and come to rest. Therefore, unlike a shotgun in particular, the stock does not have to be so designed to minimise felt recoil; which in a shotgun can be quite significant. Rifles are typically heavier and the projectile weight much lighter than a load of shot being driven by a gas column much wider than a typical rifle bore. The ability for the client to point a shotgun naturally is one that the "fitter" strives to provide and "try guns" with articulated wrist joints etc., are one of the most valued aids in achieving that custom fit. But such is expensive and all too often beyond the purse of the average shooter.

    Now, if we are aiming to build a crossbow stock, there are many pictured examples for our guidance and again Robin Allen has long provided some of these on his website. And yet as we explore the history of our beloved craft we can see that there are a bewildering number of designs throughout the ages and countries of origin; and yet the human anatomy has changed little if at all during that period. Incidentally, the inner elbow to finger crook measurement is no longer considered reliable when choosing a gun that "fits". Quite truthfully it is much like having a custom western saddle made for a particular horse and rider. But what does one do with that expensive special saddle if the horse dies? Discard it? No, but we are then bound to replace our horse with one of the same shape if we both want to be comfortable. Sorry, I digress.

    I believe that we have licence to make a crossbow to whatever shape we please, as long as we adhere to some fundamental requirements. If accuracy is paramount then it is unwise to deviate from the fact that the track and string must be at precisely 90 degrees to each other and that the level track is dead center to the prod nocks too when all is fitted together. These vital details must be established before any other shaping of a wooden stock takes place otherwise it will still be a crossbow, but not a good one. One of the benefits of CNC repeatable machining processes is that each part is the same as another and designed to be part of the whole when assembled. This is why Bill Troubridge's Excalibur, modern materials, crossbows continue to reign amongst the best. Phil A in the UK has taken the crossbow and turned it into a work of metal art that defies description and others like Robin, Tod, Geezer, and no doubt a host of other craftspeople (Did you catch that Lightly?) have largely remained faithful to what the crossbow began as.

    Enough for now.

    Pavise
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Mon May 03, 2010 10:03 pm

    Hi Pavise,

    All good points!

    First thing I would like to explain is my view on various components and their interaction mentioned when you were talking about accuracy.

    Wen first looking at a crossbow, people on average first admire the stock and many not having any knowledge of what makes an accurate crossbow completely disregard the parts that make it so and just look at how grain of the finely carved stock plays in the light . Also the ones new to the hobby usually make the same mistake of focusing on the wrong end of the order of operations and first making the stock...foolish practice indeed. So to help this problem I like to look at the process in two parts, each part with it's own order of operations > I view crossbow manufacturing process more through the prism of factory models where prod/track/trigger assembly is the actual crossbow and is to be made first...technically when these components are assembled the crossbow is practically complete...all that's left is to make a stock that fits...nothing fancy -just fits

    It is obvious that a 10 year old, a 30year old, and a 60 year old will not feel the same about the same stock. In this topic, as well as out in the real world I try to explore what makes a comfortable stock and plan to synthesize a formula similar to the one in that article, only as you pointed it out Pavise >>> for crossbows...perhaps a shorter one(that dreaded table is way too long for my aching hands )

    The things you mentioned in your post has left me with a question...

    The article I translated indeed came from an air-gun/rifle website(long
    gone now) and I do agree that it applies to a more firearm like weapon rather than crossbows. You mentioned that the anatomy of crossbow stocks though seems the same as the anatomy of the rifle stocks, when in detail they are actually two completely different animals...

    If we were to break it down into the basic differences between the two weapon types, the way they are used, and at what distances - the stock anatomy and sighting setup would change accordingly...right?

    Crossbows as opposed to firearms have a much steeper trajectory and thus will be most likely articulated to suit such an application. With this in mind I assume the sights are to be placed much higher than on firearms and thus the cheek piece should be made higher to match this increase.

    Pavise, you and Robin (and perhaps a few more people out there) have reached a certain level where crossbows are made to some very specific standards. In one of Robin's videos I remember him talking about this one crossbow that was a "general use" crossbow if I remember correctly and that that it was suitable for both, the indoor ranges, and the much bigger outdoor ranges...I believe the difference of distances between these two ranges is from 10 yards to somewhere around 70?. He mentions he doesn't like to build these general use crossbows and would rather build his crossbows for a "specific range".

    I assume the main thing with these "types" of crossbows that allows them to be more or less range specific is the available range of distances supported by the sight, but I wonder if the stock and the way it is articulated has a role in this play?

    Ivo




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Regerald
    Master Crossbowyer
    Master Crossbowyer

    Posts : 67
    Join date : 2009-11-30
    Age : 32
    Location : Finland

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Regerald on Tue May 04, 2010 9:10 am

    Ivo wrote:

    Crossbows as opposed to firearms have a much steeper trajectory and thus will be most likely articulated to suit such an application. With this in mind I assume the sights are to be placed much higher than on firearms and thus the cheek piece should be made higher to match this increase.

    It's maybe the main difference between crossbows and firearms that have to be took into account when designing stock (beside recoil).
    As I think, difference between values "a" and "b" in a table do not apply for crossbows, "b" can be even smaller than "a", especially for a long range shooting.
    Still, the best way is to try. I made a foam model for a stock, just to try how does it fit and is it hard to aim. And also to see how does it look like, if it's not of a regular shape Smile

    Sorry for a poor quality of a picture.
    avatar
    Pavise
    Dear Friend, You will be Greatly Missed.
    Dear Friend, You will be Greatly Missed.

    Posts : 128
    Join date : 2010-02-07

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Pavise on Tue May 04, 2010 11:13 am

    Ivo,

    You wrote in part:

    'With this in mind I assume the sights are to be placed much higher than on firearms and thus the cheek piece should be made higher to match this increase.'

    You're right on with this observation but there are other contributing factors to look at. One of the reasons for a higher "comb" on the cheek-piece is indeed to have the eye fall comfortably within the center of the back-sight; be that optical or another. And the latch cover on a modern crossbow often dictates this placement of sighting devices. Another reason often overlooked is the need to keep our neck as straight as possible in order that the brain receives maximum blood flow which allows our eyes to see better too. A shotgun is not sighted so and is generally presented to the oft fast moving target very quickly, thus a quick-pointing weapon is a major design objective. I suggest that a crossbow is used quite differently and that they are as Robin points out, better if built for a specific use. Again his pages, and now on this marvelous 'site, we can see the extremes where crossbows have become expressions of art or technology down through the ages, all of which are good and are to be encouraged.

    Pavise
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Fri May 07, 2010 1:33 am

    Interesting stock Regerald!
    The stock you made looks almost as if it twists at the bottom of the grip...Twisted looks inspirational!
    I love working with styrofoam, it can be shaped crazy fast with a dremel and you can test out dozens of designs in a very short time! I recently ran out and now it's time to get more. By the way, what kind of styrofoam did you use and what tools did you carve/shape it with?

    I find the (pink/blue)insulation styrofoam is the best, it is much more denser/solid and can be sanded without worrying that the beads will tear out like it happens with the (white)packaging kind.

    As for the layout I think that there is a reason to leave "b" longer than "a" and that it is actually an anatomically dependent factor and instead of shortening "b" we can just add a "c"... if I'm not mistaken, this would qualify it as a Monte Carlo stock.



    Regerald wrote:As I think, difference between values "a" and "b" in a table do not apply for crossbows, "b" can be even smaller than "a", especially for a long range shooting.

    I think "b" wouldn't be shorter, I think "Lt" would be longer, angling the butt of the stock for a correct shoulder engagement angle for distance shooting, but like you said > "Still, the best way is to try. " ...so we'll try.

    With all these ABC's in my head I begin to wonder how different is the stock made specifically for shooting while lying down?

    I haven't tried it out yet so it's all theory for now. If anyone has more info, please share...while we take a look at this awesome little buildalong ...not a real rifle, but lots of interesting details anyway. >>>Link




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Regerald
    Master Crossbowyer
    Master Crossbowyer

    Posts : 67
    Join date : 2009-11-30
    Age : 32
    Location : Finland

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Regerald on Fri May 07, 2010 6:08 am

    Ivo wrote:Interesting stock Regerald!
    The stock you made looks almost as if it twists at the bottom of the grip...Twisted looks inspirational!
    It's maybe only at this point of view, with direct daylight coming from a window..

    I used piece of an old broken lift-up garage door, it has about 1.5 inch layer of foam between two layers of aluminum. To shape, I used very sharp knife only, and some sandpaper to finish. I wouldn't recommend any dremels to use, you and all the workshop will be drown in a styrofoam dust, which electrifies and sticks to everything. Even with sandpaper, I 've gone outside to do a "dirty work".

    About "a" and "b" - I'll try to explain what did I mean. If we just put direction of a barrel (upper line in a pic.) to look little more up, with rest of a stock left untouched,
    then "b" will be smaller just because of it's definition. So it wont change any properties of a stock, but make crossbow shoot more upwards without pointing it upwards..
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Sun May 09, 2010 12:48 am

    Ahh, I understand now. I assume this is one of those "other" factors that Pavise mentioned that would limit and therefore classify the crossbow as "range specific".

    And the styrofoam dust ... I did forget to mention that I have a work related habit of never working without some sort of dust collector vacuum and that when I can I work outside, so it didn't even come to my mind, but you do make a good point Regerald....

    I tried all kinds of stuff, but a hot-wire foam cutter is the best thing.



    ...and if you get a thicker wire that you can bend to shape you can really do some interesting things with it.



    There are many examples of self made foam cutters on the internet, some run on batteries, others off of DC transformers (12-24V), but the principle is always the same.

    I just remembered a funny story. It happened to a custom R/C Airplane builder who had just finished a custom airplane for a
    customer and didn't have the hot wire cutter to cut the styrofoam much needed for protecting the plane while shipping, so he decided to use a
    regular saw to make all the cuts...ten minutes later he realized that his next door
    neighbor's lawn looks as if it just snowed.

    ...being a true gentleman he
    spent over an hour vacuuming his neighbors lawn.


    When I said "Twisted looks inspirational!" - I wasn't joking.





    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Sun Sep 05, 2010 12:22 am

    ~Sheet metal frame stock~

    Since my first encounter with "Strelets"(Big Strizh), the appearance of SCM made Twinbow, and watching the progress of crossbow builds utilizing sheet metal frame as stock structure, I have developed an interest for this system.

    The goods start with the ability to rapidly manufacture such frames with the use of precise computer controlled water-jet/plasma, going from drawing to prototype in mere days is just scratching the surface. Sheet metal frame structure is surprisingly rigid and light weight after assembly. The stock of this design is hollow, held together by round coupling nuts, and therefore there is quite a bit of space for your imagination... Built it knives, tool storage, you name it...

    BUT...Most importantly this system simplifies the idea of built-in spanning mechanisms.

    As seen on both of these crossbows, spanning levers are right at home, moving freely with room to spare.



    Despite it's awesomeness...the idea is nothing new, it can be often seen in today's products and machinery...anything from simple folding knives to structural components in land based vehicles and various types of aircraft.







    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Sun Sep 18, 2011 11:39 am


    A small addition I found a while back, sorry for holding out on you. Embarassed Smile



    And a nice follow up tutorials by Larry Potterfield of MidwayUSA. Very Happy




    I know firearm stock anatomy is quite different from that of crossbow's, but getting acquainted with the basic principles of proper stock fit yields one an opportunity to use them to one's advantage when designing a stock of his own. Hope these videos help and a big thanks to the authors, please subscribe to their channels if you like the videos. Smile

    Ivo




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Fri Jan 06, 2012 3:20 pm

    Another great piece of advise from Larry. I can see how this can be used in crossbow stock making to help in balancing the assembly...especially since crossbows can be quite front heavy due to the weight of the prod/riser(limb system)



    Always something cool out there. Smile

    Ivo




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Wed May 02, 2012 6:23 pm

    More stock making videos! ~ Complements of the Russian Crossbow Building Forum and big props to the stockmaker behind the vids.















    I'll see if I can sit dow nand reupload these vids with English subtitles, but in the mean time just let me know if you want to know what the guy is saying at any particular time and I'll explain. Wink

    Regards,

    Ivo


    Last edited by Ivo on Thu May 03, 2012 12:03 am; edited 1 time in total




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *
    avatar
    Gnome
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 399
    Join date : 2011-10-16
    Age : 53
    Location : Capitol Area Maryland

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Gnome on Wed May 02, 2012 8:15 pm

    I spent a bit of time going over this thread again while carving out my current build... very helpful information here!

    Gnome
    avatar
    Ivo
    Admin
    Admin

    Posts : 1041
    Join date : 2009-11-25
    Age : 29
    Location : NJ, USA

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Ivo on Thu May 03, 2012 4:52 am

    Glad this stuff came in handy. I remember when I was just starting to research stock making...came a long way from then, but still feel like we're just scratching the surface. Smile

    Ivo




    * *
    ~ "I don't have any special talents. I'm only passionately curious."
    * * *
    ~ "All Genius is Simple"
    * *

    Sponsored content

    Re: Custom Shoulder Stock Ideas - Videos, Pictures, Plans/Diagrams

    Post by Sponsored content


      Current date/time is Mon Jun 26, 2017 11:15 pm