SpudFiles

Hey Guys I'm not much into hunting, but I was reading an article on the Lewis and Clark Expidition. They had an air rifle. I did some reading on it wow. I thought useing all of I modern smarts I thought to build one. I looked at the side feed and it didn't look to complicated but what keeps the ball ammo from falling out the end of the barrel. I would say that it's tapered just enough to make it a tight squeez, but didn't see how since the end is several inches from where the ball rolls out into the barrel. I was also wondering how you would make the air shoot out of the but stock resivor since they didn't have ball valves and sprinkler valves in them days. I am going to make one out of brass and make the air resivor out of metal also. Any advice would be helpful. Thanks Chuck

A very detailed article on the Girandoni style rifle that Lewis and Clark used can be found here

brian the brain on this forum made a replica of the system here but I don't think he ever mounded it in an actual cannon.

I was also wondering how you would make the air shoot out of the but stock resivor since they didn't have ball valves and sprinkler valves in them days.

They did so using a hammer valve (detailed in the above article) which is the same system used by commerical air rifles today. Imagine a blowgun as the main valve, but instead of pulling it with your finger, it's struck by a spring loaded hammer.

i want to find somewhere where i can get a commercial paintball gun hammer valve so then i can make my air last longer and make a semi-auto, like your blow foreward bold bb gun but with paintballs, atleast i think it's your semi-auto with the blow foreward bolt

The solution I always suggest in these case using ready-made units is to marry a blowgun with its trigger removed and instead being struck by the hammer of a toy cap gun.

yes jacksmirkingrevenge that is a great idea. but it would have to be on of those decent cap guns. i might just try that.

i think it would be better to makethe trigger hit the blowgun lever (like on the mp5 strafer Dornep was making) because this would get more leverage on the blowgun and make the trigger pull easier. in fact i think my next project will be a regulated air powered mp5 strafer which will work the same way as Dorneps, oh wait the government restricted buying airsoft guns you now have to be on a register stoopid government so i will probably use a cap gun trigger after all.

for a paintball gun, would this have enough flow? I was thinking of using Clide's HEAR valve for a gun, but it is complecated. How bad/good would preformance be with this setup?

this is in relation to your "field legal semi-auto paintball gun" right? if you could find somewhere to get paintball gun hammer valves then i would use one of them, if not clide's valve is probably the best option.

Guys I guess yall are more experienced than me but I still don't understand how to fire the thing. Could someone draw a diagram. I want to simplify this it may be I just can't see it. Thanks Chuck

Chuck, have a look at the demo here.

Click on the instructions (Raise bolt handle, cock rifle etc.) then on the "next" arrow and charge and fire the rifle. This is exactly the same principle on which the Girandoni and most pneumatic airguns work, the difference in this case being that instead of a preloaded air tank like the girandoni's buttstock, this one has an onboard pump (like the crosman and sheridan air rifles that are popular youth BB guns). Hope this helps, if you need further clarification just ask

Thanks Guys I still don't see or understand how they made the thing shoot. I will be building a air tank in the but stock. That is the main idea behind the Girandoni rifle. Could you tell me how the air is delivered to propel the ball. Thanks Chuck

Can you not see the clear color diagrams that detail every step of the firing procedure? Obviously you can't just whip up one of those mechanisms but a hammer valve is easy to construct if you have a tank that will hold sufficient pressure.

Well I guess I can't see what your seeing. I just can't see how that would work on my gun type. I am sorry but I just started doing this stuff. Thanks Chuck

Ok, so this is the Girandoni mechanism:



What's imprtant to look at is the striker pin and the valve. There is a spring loaded hammer that moves the striker pin, which hits the valve, opening it briefly to let some air out to fire the projectile. The valve spring then closes the valve again and the cycle can be repeated. Here, I've made it into an animation so you can understand better (click on it to open in a new window for better quality):

Thanks I understand and I appreciate your time. Now what type of valve would I use on my rifle. I don't know where to get one like they have in the picture. Thanks Chuck