# Hunting with a Jorge Sprave creation



## dang magpies (Jul 3, 2013)

Recently I have been getting back into the hunting game and I've been looking for a capable weapon . Watching a Jorge Sprave video I noticed his bull-pup crossbow that shoots ball ammo . It was very accurate and hard hitting , definitely more than enough to go through a bird or rabbit . This also allows me to use larger balls because it is much more powerful . He seemed to be using a 20mm Steel ball but I thought a 15mm lead ball might be more destructive . So I ask you guys do you use any Jorg Sprave inspired creations for hunting or any other contraption beside the traditional fork


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## Sunchierefram (Nov 16, 2013)

I know people have used starships for hunting and they sure aren't traditional. And I don't know if anybody's used a stickshot for hunting but they also aren't very conventional. But anyway, Joerg makes some pretty destructive stuff and I think they would easily be able to be used for hunting.


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## Henry the Hermit (Jun 2, 2010)

Any frame that can handle rubber capable of propelling a projectile with enough force to kill the desired game is suitable for hunting. if you are comfortable with it, some more than others of course. I haven't seen any of Joerg's creations that are particularly suited for hunting.

The best hunting slingshot is the one that you can consistently hit with and that produces enough power to get the job done. For what it's worth, more game has probably been killed with a forked stick and inner tube rubber shooting rocks than anything else.


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## benzidrine (Oct 14, 2013)

While Joerg's designs certainly look fun, I don't think they are the ideal choice for hunting.

The balls while powerful wouldn't have the penetration for larger game and therefore humane killing, so you just aren't gaining much through that extra power over a regular slingshot. (Except in an emergency situation where all bets are off of course).

If you are going to build something I would just build a crossbow and buy some broadheads (where legal). You could use rubber and they aren't hard to build. That way if you have a 100+ pounds of rubber you could reasonably take medium game and 150+ pounds large game while still being just as useful for small game with blunt points.

This tutorial is pretty decent just replace the PVC with rubber:






Do whatever is fun for you though.


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## Charles (Aug 26, 2010)

Rubber based crossbows have a number of disadvantages.

1. There is a significant loss of power if a rubber powered weapon is left in cocked mode for a long period of time. That is due to the heat radiation from the bands. This phenomenon does not seem to affect bows as much. So you might want to consider one of the designs in which the rubber powered crossbow is cocked only immediately before the shot.

2. Rubber becomes much less effective pretty quickly in cold weather. Depending on where you are hunting, most small game seasons occur in the fall and winter, which might be in pretty cold weather. A hand held slingshot can be easily kept under your coat until just before you shoot, which will lessen the effect of cold temperatures. That would be pretty hard to do with a crossbow or rifle type device.

3. A rifle or crossbow design is just not as compact as a hand held slingshot. So it is more difficult to transport and to carry in heavy bush. It is also more likely to cause alarm if anyone sees you using it.

Of course there are compensating advantages ... mainly most folks will be more accurate with a slingshot rifle than with a hand held slingshot.

In general, I would suggest that using very heavy bands and monster ammo will not be a good idea. The heavy bands will just make it much harder to cock the weapon. And the resulting increase in power will be overkill for small game hunting. Standard bands and .45 - .50 caliber lead will handle about anything in the small game department. If you want to go after larger game, then use a bow and arrow with broad heads.

Cheers ..... Charles


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## benzidrine (Oct 14, 2013)

Charles I agree with almost everything you said except there is one thing I don't understand.

>1. There is a significant loss of power if a rubber powered weapon is left in cocked mode for a long period of time.

I agree there is a power loss but isn't it in usual temperatures about 30% over time? Seems like you could counter that by simply using a heavier draw.

Also because the power stroke of a crossbow is so tiny I imagine the inefficiencies of a crossbow against a rubber powered "crossbow" would probably even out.

Or have you seen much greater drops than 30% over time? I know you have made testing setups so you might have greater knowledge.


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## Charles (Aug 26, 2010)

The degree of loss will depend on the ambient temperature. If it is 0 degrees C (32 F), then the loss will be pretty extreme ... not sure how much, as I have not tested it. But if it is 35 C (95 F) then there might actually be some increase.

You are correct that there are some ways of compensating. You can use heavier bands, but that makes it harder to cock the thing. And heavier bands do not necessarily result in higher velocity of the projectile ... it is a tricky thing. You can use a long "barrel" to increase the draw length; wider fork separation will also increase the draw length. Increasing the draw length is a more certain method of increasing velocity. But a longer barrel and wider fork width make the thing more unwieldy.

Although it has a fairly short power stroke, a compound crossbow will be very hard to beat with a rubber powered device.

Don't get me wrong ... I am not saying it is a silly thing to do. I have made a slingshot crossbow myself over 20 years ago. At the time I was under the misapprehension that heavier bands would yield higher velocities ... but it just was not so. I wanted something fairly compact, so I made it short. What I really needed was a much longer draw length. I could get that by lengthening the "barrel", but that made it too unwieldy for my taste. Another approach would be to have the bands double back over rollers at the fork tips so that there would be no slack length ... that would increase the acceleration path of the ammo by the slack length of the bands. Of course there would be some loss in the roller arrangement. In the end, to my mind, it was simpler to just use the old classic hand held slingshot. But as in most things, your mileage may vary.

Cheers ...... Charles


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