A 50 pound crossbow pistol to fire a ball valve.

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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boyntonstu
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A 50 pound crossbow pistol to fire a ball valve.

Works OK but it needs some tuning.

The oxygen bottle and a gauge plus ball valves at the end of the feed hose allows me to fill the chamber to any pressure less than max.

I can get at least 10 shots per fill.

I plan to use the same barrel that fits the Trom-Boyn for comparison shots.
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Gun Freak
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Wow that's pretty nice, must be pretty comfortable to shoot, eh?
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JDP12
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As an avid archer id say what youre doing is tantamount to dry firing it. No bow is meant to be dryfired, an even though some force is being transferred, i dont think enough. Id be extremely careful if i were you
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Marffy
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Would you say it was worth tearing apart a cross-bow pistol? looks pretty good though.
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boyntonstu
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Gun Freak wrote:Wow that's pretty nice, must be pretty comfortable to shoot, eh?
Thanks.

It is a prototype for testing.

However a few points:

I am a righty yet it feels good pulling the trigger with my left hand.

Most rifles and shotguns have 14" between the butt and the trigger.

The end of the plywood that points down at the chamber end is 14".


Instead, I would fire it lefty, add a right hand grip at 14" and have the chamber rest over my shoulder.

Similar to a Thompson sub-machine-gun.
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boyntonstu
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Marffy wrote:Would you say it was worth tearing apart a cross-bow pistol? looks pretty good though.
Can you make a spring, pistol grip, and a safety for $15?

That's what they sell for on ebay.

http://cgi.ebay.com/NEW-Hunting-Archery ... 230718674c

BTW I didn't tear anything apart. It goes back together, but I wouldn't want to do it.

It fired an 80 gr bolt at 164 fps with terrible accuracy.
Last edited by boyntonstu on Tue May 11, 2010 6:49 pm, edited 1 time in total.
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boyntonstu
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JDP12 wrote:As an avid archer id say what youre doing is tantamount to dry firing it. No bow is meant to be dryfired, an even though some force is being transferred, i dont think enough. Id be extremely careful if i were you
I disagree.

Dry firing a crossbow is a no load situation.

Pulling a 3/4" ball valve open is further away from dry firing than shooting a bolt.
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JDP12
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Yes i know. Thus all the energy from firing gets transferred into the limbs of the bow instead of something else, normally an arrow/bolt. Ive seen limbs literally explode because theyre not meant to handle all of that energy. I dont know how much force the valve takes o open, but i doubt its a ton.

Also please edit your posts instead of triple posting.
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boyntonstu
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JDP12 wrote:Yes i know. Thus all the energy from firing gets transferred into the limbs of the bow instead of something else, normally an arrow/bolt. Ive seen limbs literally explode because theyre not meant to handle all of that energy. I dont know how much force the valve takes o open, but i doubt its a ton.

Also please edit your posts instead of triple posting.
The limbs are steel (1 piece). Did you ever see 50 pound steel limbs explode?
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JDP12
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Ah. Well i didnt know they were steel. Thpught they were jst traditional laminated wood. Sorry
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Marffy
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boyntonstu wrote: Can you make a spring, pistol grip, and a safety for $15?

That's what they sell for on ebay.
wow, thats cheap. dint know. I'd definitely try this for that price.
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