Yet another QEV and 3/2 valve cannon

[Xenophile]

My latest creation. As the title suggests, I using a QEV and 3 position 2 way valve with a 300 psi input from a regulated HPA paintball tank. I have two different barrels, one for 3/8 inch (9.5 mm) steel shot and another for .30 caliber steel shot. The 3/8 inch barrel is currently muzzle loading, but I plan on eventually installing a breach like the one I made for the .30 barrel. The projectiles are held in place with neodymium magnets before firing. The stock is made from some cheap pine that I stained with a polyurethane stain. Eventually I plan on making an integral tubular magazine for the .30 barrel from a "T" fitting.

This is a test using some homemade ballistics gel. I made a 4 Liter block with a standard 10% mix. The 3/8 in shot went in 7 inches and the .30 shot went in 5 inches.

Overall, I'm very happy with this build. I'd love to hear your thoughts!

[jackssmirkingrevenge]

I love the look, and good performance too! Always nice to see people pushing the envelope when it comes to pressure.

[Xenophile]

Thanks JSR, I'm glad you like it!
I've completed a gravity fed magazine ( 10 shot capacity for .30 caliber shot) which is working fairly well, but I am having some issues with double feeding.

I'm using a "detent" system with neodymium magnets to keep the shot in place, but this seems to be unreliable. Anyone here know of a good way to construct a magazine (or other device) to minimize double feeds and improve reliability?

I also got another picture showing the completed cannon with all accessories. This gun continues to be an absolute blast to shoot, and gets fairly good gas efficiency. I get around 50 shots from a tank filled to 100 bar (1450.38 psi).

Still to come is a breach for the 9.5mm barrel and maybe a suppressor, although it's only slightly louder than a traditional pellet rifle. Maybe better optics than my hastily crafted laser?

[jackssmirkingrevenge]

I'm using a "detent" system with neodymium magnets to keep the shot in place, but this seems to be unreliable. Anyone here know of a good way to construct a magazine (or other device) to minimize double feeds and improve reliability?

One idea would be to have a pressure actuated element that physically blocks the next projectile in the magazine, here are some rough ideas I had sketched:





A spring-loaded detent might also do the trick, it's what my Brazilian Fionda uses and it works quite well, no double feeds.

[Xenophile]

Thanks for the idea JSR!
I continue to make more modifications and improvements to this thing.

For example, I've added a scope, and a proper laser sight (not shown, on the other side) for greater accuracy at longer ranges.

I've also added a proper bolt action/integral tube magazine setup for the 3/8 in (9.5 mm) barrel. The tubular magazine holds 25 shots.
Finally, I had some fun with an uncarved Halloween pumpkin.

Entry

Exit
You can even see when I began to run out of air!

[jackssmirkingrevenge]

You can even see when I began to run out of air!

we can!





Nice work!