High Draw Weight PVC Crossbow Build

It's been awhile, but I'm getting back into crossbow building.

This time around, I want to see if I could create a crossbow out of a heat formed PVC bow/prod strong enough for hunting medium-size game. I have this 2 inch Sch 40 PVC pipe that's been laying up in my garage (meant for airgun build I never went through with), and I'm thinking of flattening and tapering it into a bow in the same way Nick (Backyard Bowyer) did with a 80-pound build he did several years ago: https://www.youtube.com/watch?v=4nYHUbzApc4.

I'm aiming at a 32 inch nock-to-nock width with a drawlength of 13-14 inches, give or take. To form the prod, I'm going to first flatten the 2" pipe to a thickness of 1-1/4", then form the taper. Like Nick, I'll be cutting out a V-groove at the tips to lighten the limbs and form a secondary taper, and then adding a bit of reflex to hopefully get some more energy efficiency and speed out of it. I'm hoping to get at least 160 fps out of a 600 grain bolt. I reckon this prod should give me at least 150 pounds of draw weight when finished, judging by the 100 pound prod from a 1-1/2 PVC pipe Nick made for his crossbow.

Hope that works out for you.  BTW, we don't think of 150#s as a "high draw weight" crossbow   400-500# is getting up there.  Remember the rule of thumb that a crossbow of X draw weight is about the same power as a straight bow of half that draw weight.  So a 150# crossbow is about equal to a 70-75# straight bow.

@kenh

Ah, of course :p - I was just speaking relative to the PVC bows I've seen so far. I'm hoping to get at least 45 ft.lbs out of this build.

In my opinion I wouldn't use a PVC crossbow for hunting, not to discourage you or anything. The problem with PVC it's way too heavy even if you taper the tips by tapering in width and thickness. I saw a video of Nick(BackyardBowyer) making a stovetop horsebow with tapered tips the bow was 45 lbs and shot 147 fps. There is also a video of him shooting a pvc horse bow with siyahs that was highly reflexed. It was around the same weight as the other one 45 lbs but, since he highly reflexed it at the center it had 9 inches of reflex it shot of speeds ranging from 172 to 169 so pvc bows can compete with fiberglass laminate bows, sinewed back bows under the right circumstances. But they tend to be really unstable and can shatter if they break.

Why don't you try putting fiberglass rods in the pipe before you taper and recurve the ends? The disadvantage of pvc is also it's very same strength it's flexiblity. You could use a smaller diameter pvc pipe while still enabling it to being a 150 lb prod if you just take a bunch of fiberglass rods different sizes 1, 3/4, 1/2, 1/4. This will enable you to get a prod that's decently fast in speed since even though the fiberglass rods will add weight they will also add stiffness. Than if the pipe was without fiberglass tent rods and a larger diameter which would just add weight due to the mass of the prod making it less efficent.