SpudFiles

I am looking at a 2" valve and am worried about the recoil. Would like to hear from someone who has personally fired or has known someone who has a gun with a 2" valve with a CV of atleast 80+. It is a Goyen 2" dust collector valve. Link to valve is below.

http://www.piiny.com/goyen/pdfs/CA_RCA_50T.pdf

The muzzle energy is @ 276 ft/lbs if that helps with 150 psi

Thanks for the help.

Where can i buy that????

I am buying from

http://www.piiny.com/goyen/tseries.htm

I'm not sure of the cv of a 2" qdv but I know they have serious recoil especially with heavy projectiles.

Reason I am asking is it would be almost half the cost to use a 1.5" valve. Talked to an engineer at Goyen and he said I should stay away from 2" due to recoil and stay with a 1.5". Guy was very intelligent but was not a spudder so figured I would ask on here.

I am wanting to make a really nice gun so it is worth it to spend extra $ to get a nicer valve but if I can only use 2" at 100 psi and I would be able to fire 1.5" at 150 psi then I will be better off with smaller valve.

Both valves can be used at 150 psi just worried about recoil.

Atattack wrote:Both valves can be used at 150 psi just worried about recoil.

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A muzzle brake and recoil absorbtion system would make interesting design features.

Ronnie Barrett didn't see the 50 BMG round and think "This round is fuçking awesome, I will take out some powder to make it comfortable to shoot in a rifle."

Ronnie Barrett saw the 50 BMG round and thought "This round is fuçking awesome, even though I know nothing about firearms or engineering I will make a rifle that can fire it comfortably"





Footnote: J.D. Jones did take out some powder and made an awesome silent sniper round, but that's beside the point.

My 2 inch port QDV videos are in this youtube channel. Check the uploads. The worst recoil is when oversize barrels are used. A three inch barrel with Gatoraid is the highest recoil item shot. My shots are all 100 PSI or less.

http://www.youtube.com/user/Technician1002

With lower pressure and lighter projectiles, the recoil is quite manageable. The tshirt shot below is about 35 PSI.

Trust me on this one, You do not want to shoulder fire a Gaitoraid in a 3 inch barrel at 100 PSI on a 2 inch high CV valve. This one left a bruise.
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HMmmmm, you bring up some good points as usual JSR, . I am using a 3" aluminum schedule 40 for the pipe that is 48" long. When making a muzzle brake do I just drill holes in last 6" of pipe?

Any ever make a recoil absorption system? I was planning on having a curved piece of metal come down chamber to rest against shoulder. The gun is going to be a shoulder based launcher, so hopefully that will make it easier to incorporate a absorption system.

I plan on using a 3" barrel to launch water balloons so will be heavy and oversized, so that is why I will either need to go to 1.5" or compensate for recoil, JSR has me wanting to compensate now, that sounded bad, .

Start with low pressure. I have launched raw eggs without breaking them.

Some further reading:

http://www.spudfiles.com/forums/muzzle- ... 22706.html

http://www.spudfiles.com/forums/handhel ... 21450.html

The NTW-20 is a good source of inspiration.

After reading muzzle brake thread I think I am leaning towards a suppressor because will have numerous people around when using this and am a little concerned about people saying muzzle brakes can be very loud. Anyone know how suppressor compare to muzzle brakes as far as recoil efficiency?

That recoil system looked pretty complicated to make. I am trying to figure out how I can do it with the butt coming down from the chamber rather than traditional way of having it built into back of stock.

I don't think ~300 foot-pounds M.E. is much to worry about.
If, for example, your projectile weighs 1/3 of your gun weight, you'll be absorbing somewhere around 100 ft-lbs of recoil. That's a lot, but I'm sure your proj/gun weigh ratio will be nowhere near this high.

Consider that 400+ foot-pounds of recoil energy is entirely survivable, but dangerous and often comical for those around you.

After a quick calculation I believe I've personally taken somewhere between 100-150 ft-lbs with an unpadded wooden stock. It was quite unpleasant, but still managable (this was with an old combustion gun shooting a barrel full of water).

Edit; If you're using a large chamber at high pressure you'll want to take into account them recoil from the gas itself. Add its recoil energy to your total. Air weighs ~1.2 grams/liter and will be traveling around 300 m/s (1100 fps) worst-case scenario.

I could be doing the GGDT calculation incorrectly then, not positive about that M.E. #. I am using 150 psi, projectile will weight 6 oz. Valve is 2" with 88 C.V. Barrel is 3"x48" and Chamber is 3" x 48". Open time is 70ms. I figured with a projectile that heavy is would kick pretty bad.

Your opening time is way to slow. Play with this number and you'll see you could be getting ME's of over a thousand ft-lbs, which sounds reasonable.

Still with a 6 oz projectile I wouldn't worry about it too much. That video JSR posted had way more recoil than this will. It all depend on how much your gun weighs.