SpudFiles

All the parts for this cannon are totally off the shelf starting with the re-purposed 50 caliber muzzleloader barrel. I am presently firing it with 250 to 300 psi air from a good quality 250 psi stirrup pump or my re-purposed 30# propane tank with pod pop-off protection at 315 psi. The 300 psi air is obtained by piggybacking an R-22 compressor onto a 120 psi shop air compressor. The lowest pressure rated component in the system is the Alpha QEV rated at max 250 psi with a burst pressure of 2 to 3 times that. With a properly rated homemade piston valve the operating pressure could easily be quadrupled. The energy is obtained by using 0.7 liter (from the gun stock aluminum tank) of 300 psi air for each shot. This means that the initial pressure available at the breech is 300 psi and the final pressure at the muzzle before the bullet exits is 268 psi for a uniformly accelerated bullet in a 24" barrel with very little decrease in initial firing pressure. No chrony data yet, just bullet splats of 1.25" diameter from a 182 gr. .495" round ball using a steel plate 3' from the muzzle. I can disconnect from the 30# tank for a remote shot or remain tethered for target practice. I also have a 1.5 liter HPA portable tank. It takes about 10 seconds to reload this gun. It's more fun than b***k powder. This gun is less than 8#'s has only 3 moving parts and is very sturdy. The barrel never needs cleaning. The tank size was chosen for it's comfort as a stock and the tank volumn was reduced with epoxy resin to 42 cubic inches to minimize air usage while still providing high mass air flow. The gun is loaded just like any muzzleloader. A 0.495" pre-lubed ball is just large enough to slide down the barrel with only the weight of the ramrod. A tap on the ramrod lodges the ball into the opening of the 3/8" breech nipple threads, (great for down hill shots). The QEV is an Alpha 5UPH4. The trigger is the 1/8" push button vent valve used as a pilot valve. This gun is also a fine arrow launcher and makes a pretty decent shotgun at 10 to 15 yards with a 180 to 200 grain shot load, (about the size of a 410 load). Videos of the gun can be viewed on my Youtube channel at: I am also shooting it with CO2 (stabilizer set at 400 psi).

http://www.youtube.com/user/mpmrla?feature=mhee


(Click on each pic to enlarge)
This is a pic of the finished cannon with cord wrap epoxied in place
and a red dot scope added. The Trigger is the 1/8" push button valve
( "M" in the diagram) that is plumbed toward the muzzle. It works great as a trigger and requires an increase in pressure to trigger the gun if you increase the operating pressure.




This is a pic of the cannon compared to a Gamo viper and a Beeman 0035


In this sketch of the gun all parts on the gun are laid out in the same
orientation as the sketch. The trigger is "M" and the fill valve is "k" (which can also be a foster nipple). Also, I have since added a 2" extension between parts "G" and "F" to place the trigger at a more comfortable distance. This 2" extension can be a tee so that by adding another vent valve you have a way to depressure the gun without shooting it.


182 grain bullet splats compared to a .22 cal and a .177 cal pellet. The
bullet splats indicate about 400 to 500 ft/sec muzzle velocity.


In this pic a 364 grain homemade slug is compared to a 182 grain ball
and the slug splat on the right.

That's a nifty fifty.

mpmrla wrote:All the parts for this cannon are totally off the shelf

That's what I really like about this one, great job and very well put together

Nice, and elegant. I don't see any trigger mechanism, are you just using your thumb to press the pilot schrader at the moment?

Also no loading mechanism yet, are you going to implement these things or just use it as is?

I wish it was legal to bring a proper barrel into my country.

Still nice job.

wow thats really cool. just cut down on chamber size. @300 psi a chamber even 1/3 of the one you have, will do

During the initial construction of this gun, I only had my shop
air compressor with 120 psig air and a .35 liter tank. The larger tank gave me better performance. When I got my 250 psig stirrup pump I reduced
the size by 40% and still got very good performance. Now that I
have 300 psig available I left the internal volumn at 0.7 liter so
I could still get good performance at 200 to 250 psig. This middle
of the road volumn also allows me to use the gun at 120 psig especially
for shooting arrows. I left it that way for more flexibility. Thanks for the
interest and the advice. This is a pretty cool site.

Nice job, I like how there's no custom stuff on it, I like off the shelf stuff that looks good Good work!

Thanks Man.
Also thanks for all the other comments
by others that I missed.

Excellent work. What you used as a tank?

juandrex18 wrote:Excellent work. What you used as a tank?

Do not revive dead topics,just pm OP
Anyway the answer is short he is using 24 ounce paintball tank
like that http://www.amazon.com/PMI-Pure-Energy-A ... 89&sr=1-32

Well, now that it's been revived:
I'm curious how you adapted the muzzle-loader barrel to the plumbing fittings. Is the barrel threaded NPT?

@mpmrla..." where art thow" matthew I need some pointers
on your cannon.

Jonesy, what do you need to know?

@zeus...if you read this thread - mpmrla's .36 and .50 cal
ive been talking about it there, when i should be here
I did mention im a noob on here, didn't i

Residing in Southern Perth, "Straya

Skywalker wrote:Well, now that it's been revived:
I'm curious how you adapted the muzzle-loader barrel to the plumbing fittings. Is the barrel threaded NPT?

I bored out the straight breech plug threads, slipped a 1/2" pipe
into the hole and ran a small weld bead around the pipe. If you
can't weld you could bore a small hole throuh the top of the breech
just a hair above the chamber and all the way through the top of the
pipe insert to the other side of the breech and pin the insert in place.