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Posted: Mon Mar 19, 2007 6:39 pm
by judgment_arms
Arrg, that be a slick lookin’ arm you got there, matey!
Where’d you get the .45cal barrel?
Here’s a project for you: get a green mountain .50cal muzzle loader barrel and run it off 30bar., now that would be slick!

Posted: Mon Mar 19, 2007 11:50 pm
by Brian the brain
obtaining that would be impossible...

Posted: Wed Mar 21, 2007 3:14 pm
by Brian the brain
I'm thinking of building it into a long muzzle loading musket some time in the future...


I'd like to build a hammer that knocks open the ballvalve on a longer version...

That would look too bulky on a pistol..

Posted: Wed Mar 21, 2007 7:30 pm
by jackssmirkingrevenge
Brian the brain wrote:I'm thinking of building it into a long muzzle loading musket some time in the future...
What happened to your girandoni style breech loader?

Posted: Wed Mar 21, 2007 11:03 pm
by Hawkeye
I'm working on a long musket that uses a hammer to knock open a small one way valve to exhaust the pilot. Trying to work the pump into the butt section as well. It just seems a bit tricky to work out a way to pump it that way. I can get a swivel fitting for air tools that will allow the pump to be swiveled sideways and pumped with the gun lying on the ground.
There was an old design that housed the pump in the stock with the gun pumped vertically up and down. The air chamber encircled the barrel and a hammer valve was struck by a hammer.

Posted: Wed Mar 21, 2007 11:45 pm
by Brian the brain
You need to start showing some pictures...

Posted: Thu Mar 22, 2007 12:19 am
by jackssmirkingrevenge
Hawkeye wrote:There was an old design that housed the pump in the stock with the gun pumped vertically up and down. The air chamber encircled the barrel and a hammer valve was struck by a hammer.
It would hardly be a hammer valve if it was struck by something else eh :roll:

Image

*ahem* yeah, you mean the Bate air rifle, circa 1780.

Posted: Thu Mar 22, 2007 6:52 am
by Hawkeye
Yeah I was just stumped as to what you would call the part of that gun that doesn't actually have a flint attached to it.
Of course blowguns are said to use hammer valves that are only pushed open...
Brian, I still haven't decided on entering the contest yet. Pictures would eliminate that possibility.

Posted: Thu Mar 22, 2007 7:05 am
by ShowNoMercy
How does the hammer trigger the valve? Is it like a burst disk broken by a spike or something?

Posted: Thu Mar 22, 2007 7:15 am
by jackssmirkingrevenge
ShowNoMercy wrote:How does the hammer trigger the valve? Is it like a burst disk broken by a spike or something?
Imagine a blowgun valve - instead of pressing on it with your finger, it's struck by a spring loaded hammer, in the same way the hammer on a firearm strikes the firing pin. Once the momentum of the hammer is countered by the valve return spring, the valve closes again - this allows for more than one shot from a single air reservoir, and is basically how all modern pneumatic air rifles function.

Posted: Thu Mar 22, 2007 7:17 am
by ShowNoMercy
So you would have to get the amount of time that the hammer activates it to match with the amount of air released and the length of the barrel and weight of the projectile? That sounds complicated, I will stick with simple things, like Supah valves. :wink:

Posted: Thu Mar 22, 2007 7:26 am
by jackssmirkingrevenge
ShowNoMercy wrote:So you would have to get the amount of time that the hammer activates it to match with the amount of air released and the length of the barrel and weight of the projectile? That sounds complicated, I will stick with simple things, like Supah valves. :wink:
This is how variable power air rifles like the Talon work - they have an adjuster that alters the hammer spring tension, thus varying the amound of air that is released per shot.

Such a system is only practical in small calibres, and will only give devent power if used with pressures in excess of 1,000 psi - so for most spudding applications, you're better off with a Supah valve anyway :wink:

Posted: Thu Mar 22, 2007 7:31 am
by ShowNoMercy
Damn, thats a nice little setup they have there, my only thing is the price, for that amount you could get a 10/22 and in my opinion a real rifle is much more fun. I also happen to have one so my view is a bit biased...

Posted: Thu Mar 22, 2007 7:38 am
by jackssmirkingrevenge
Air rifles are fun, but when you approach 100 ft/lbs, a rimfire is a much better idea - it's more compact and lighter than an air rifle, doesn't require cumbersome and expensive filling equipment - all you need is a pocketful of cartridges - and with a decent silencer it can be even quieter than an airgun.

The Russians and Israelis both use 0.22 rimfire rifles as urban snipers because of they are discreet, accurate and with more than enough power at the close ranges involved. I've read unconfirmed reports that US forces are using high powered air rifles for sniping in Iraq, although for the reasons I've detailed above it's not the best of ideas.

Posted: Thu Mar 22, 2007 7:42 am
by ShowNoMercy
Yea I have seen them before, and on the topic of big rifles in Iraq, I know that the mercenary force, Blackwater, use them. But my roommate is convinced that big (.50 cal) rifles are illegal to use by the geneva convention so I dont know. The blackwater guys are pretty bad ass, they came to my school to use our ship to practice forced landings and entries, but I also know that they are in some hot water for some of the things they have done in Iraq.