Gentlemen in narrowing my question I'm a little confused on the draw weight of a steel prod crossbow of the 15th century as carried by the average soldier. I know the "siege" crossbows are 1000lbs plus in some cases but what about the bows used in the field during open combat?

Draw weight for 15th century military field bows?
That's a little like asking horsepower for mid-20th century automobiles... it varies.
Light infantry and cavalry bows, like the ubiquitous Padre Island bow might draw 300-400 lb. and be drawn with a gafa cocking lever (goats foot)
German-style cranequin-bows, as used by some horse archers, might draw as much as 1000 lb, but I would expect more like 500-700 lb. (that's a number off the top of my head... I know Metropolitan Museum tested such a bow back in the 1930's under Bashford Deane. As I recall, their bow drew something over 700 lb, and though there were problems with the way their tests were conducted (they were trying to determine power, but used a bolt that was wayyyyy too light) I see no reason to doubt the efficiency of their scale.
Ralph Payne-Gallwey had a large military Arbalest that drew 1200 lb, and cast a 4 ounce bolt @ 450 yards. Total weight of the weapon was about 18 lb, not much less than the weight of a WwII BAR automatic rifle, which was carried by one man, albeit generally a strong man. so if you figure a maximum of 1000 lb. for a late 15th century crossbowman in the field, you'll be about right.
Any bow much in excess of 350 lb. will require some sort of spanning device stronger (and slower) than a simple belt-hook.
Does that answer your question? Geezer

Geezer that does help thanks. One last question on this thread. Would the Padre Island style bow be considered military issue for combat or more of a hunting bow? Thanks again for the help.

The original Padre Island bow came from a shipwreck (1554) IT WAS ALMOST CERTAINLY DEFENSIVE WEAPONRY FOR THE SHIP... SPANISH REGULATIONS REQUIRED ALL SHIPS TRADING TO THE INDIES TO BE ARMED. IT'S VERY PLAIN, WITH NO DECORATION AT ALL. THERE ARE MANY SIMILAR BOWS... A BIT NICER IN FINISH, AT THE ARMORY IN MALTA, AND A FAIR NUMBER IN THE ARMERIA REAL IN MADRID.
I THINK OF THEM AS THE M-1 CARBINE OR AK-47 OF THE LATE 15TH CENTURY. SPANISH ARMIES EMPLOYED "JINETE" LIGHT CAVALRY WHO WERE ARMED WITH JAVELINS AND CROSSBOWS. THE PADRE ISLAND BOW LOOKS IDEAL FOR SUCH A PURPOSE... SO MOST LIKELY IT'S A LIGHT MILITARY BOW.

Hey guys, sorry about the all-caps again. We can blame that on the cat, who cleverly stepped on just the right key as I was sending. No cream for you, Zebulon.