High-Power Copper Sniper Rifle

[Velocity]

After many failures, tears, and dreams shattered, I finally managed to complete a working copper pneumatic. Its not the best, nor is it even pretty, but I am really proud that I finally conquered copper 8) .

<img src="http://www.spudfiles.com/uploader/uploa ... umatic.JPG">

Specs
Chamber: 1" x 60" Type L Copper Tubing
Barrel: .68" x 72" 6061-T6 Aluminum Tubing
Valve: Copper piston valve, 1" inlet and 3/4" outlet. Piston is constructed from UHMW; exhaust valve is 1/4" Detrol QEV piloted by a 1/4" blowgun.

More pictures:
<a href="http://www.spudfiles.com/uploader/uploa ... JPG">Valve Detail</a>
<a href="http://www.spudfiles.com/uploader/uploa ... >Downrange View</a>
<a href="http://www.spudfiles.com/uploader/uploa ... PG">Barrel Support</a>

This cannon was built strictly for performance. The long paintball barrel, combined with a decent 1.8:1 chamber to barrel ratio, provides a great amount of power. According to GGDT, at 125 PSI with compressed air, this gun should be able to break 800 FPS. If I pump it up to 250 PSI, which is feasible due to the high pressure construction of this pneumatic, it will be able to break 1000 FPS. If I can get my hands on some helium... then the real fun begins .

I am actually somewhat surprised at how low the velocity figures are; I have seen many paintball cannons on this sight that also can get 800 FPS at 125 PSI; this is using 24" or under barrels that have a diameter of over .7"! For some reason, I think the owners might be a little optimistic on their figures... I am probably a bit optimistic myself.

I find this cannon to have a nice weight, even though it is extremely long. I plan to add a laser scope to it sometime soon, to make aiming easier. I might also add a breech loader in, because muzzle-loading a .68" paintball down 72" of .68" barrel is NOT fun at all.

I don't think that this cannon is complicated, so I doubt that there will be too many questions. I hope to get up a video within a week or two; I have a tennis tournament and a 25 page paper due within the next week or so; luckily my AP exams are over, so that frees up some time. I'm going to see if I can break some PVC pipe with frozen paintballs; it is probably unfeasible, but I have never played around with this type of power before, so its worth a shot .

Though its far from the best copper cannon, I am still really proud of it (trust me, success after multiple failures spanning over a period of nearly eight months feels REALLY good). If you have any questions, feel free to ask.

Thanks for looking.

PS: And yes, I am calling it a sniper, and I am calling it a rifle... though it does not have a rifled barrel. DEAL WITH IT

[ammosmoke]

I like it! I think you should go and get a laser site ASAP, because they are totally cool and convenient.

[jackssmirkingrevenge]

And yes, I am calling it a sniper, and I am calling it a rifle... though it does not have a rifled barrel. DEAL WITH IT

Well, Steyr call this monster an Anti-Material Rifle in spite of its smoothbore barrel, so I guess you have every right

Nice work, and with those dimensions, I expect some killer high-velocity performance, so damage pics/vids s'il vous plait

[spudthug]

wow... that is huge!! where do u store that thing lol.. u should have made interchangeable abrrels so u could store it somewhere hehe.. nice job rmich

[joannaardway]

Congradulations for sorting the copper issues. Should have interesting performance.

[mark.f]

Great job on the construction, rmich! I knew you'd figure it out sometime.

I was interested in that aluminum barrel. How did you attach it to the gun? It looks like some sort of epoxy?

[ShowNoMercy]

Does a paintball stay inact in a barrel that long?

[Mitchza89]

Thats a great looking cannon mate. Getting pistons to work at that size are so so tricky, I spent days trying to get my 3/4in to work but I just gave up. A job well done, I hope to see damage pics soon.

[jackssmirkingrevenge]

Getting pistons to work at that size are so so tricky, I spent days trying to get my 3/4in to work but I just gave up.

Really now

[Velocity]

Thanks for the comments guys. I had no problems with the piston whatsoever. I popped it in the piston seat, and it worked flawlessly, with no changes necessary.

Mark, I used metal epoxy to hold the barrel in place. Considering that it is not holding any pressure, I feel completely confident that it will hold up to all abuses.

Paintballs so far have not popped in the barrel; the interior is very smooth, and I suppose the sudden rushing of air doesn't damage them.

I did some very limited testing today. I shot at 60 PSI and 90 PSI (the most pressure that I have ever used, oh boy ); i am almost up to your 300 PSI Mark . The performance was pretty solid, but my laser sighting wasn't working properly so I didn't get to shoot too much. At 90 PSI, it ripped a hole in a 2-liter bottle; not sure whether that is good or not for a paintball.

I thought this gun would be pretty quiet; it is VERY loud. I guess I have never taken a gun to such high pressure, but I can't imagine how loud a 250 PSI shot would sound!

I took 3 crappy videos, with the gun shooting at approximately 70 PSI each time. I don't think that I will post them, just because they are nothing spectacular; you here the gun fire, and then you see plastic bottles filled with water topple off of the platform which they were standing on.

When I make the real video, I will probably pump the compressor up to 100 PSI and make a few shots then. I'll probably shoot my old old math textbook (way back from the days of Algebra I ), a few better shots at bottles, plywood/particle board, and perhaps a piece of 4" SCH 40, just to see what happens.

[lukemc]

you said your piston is made of UHMW what is UHMW? i have to disagree with you saying its not pretty i think a copper piston gun is beautiful. think the QEV exhaust is a bit overkill but if it works for you thats cool. very nice door by the way.

[veginator]

your asking if ripping a hole in a plastic bottle with a paintball is good. its AMAZING. i couldnt go all the way through a plastic bottle with my 1000fps pellet gun. [/b]

[Velocity]

UHMW is a type of polyethylene plastic that is light, pretty cheap, and easy to machine (this is what I have heard; I didn't do any machining on my piston).

The QEV is overkill, but I do not mind; it is only on there temporarily to get maximum power; it will soon be transfered to my newest pneumatic when it approaches completion (not for a while).

Even though I just finished this project, I want to start another one . I just enjoy building things, seeing how they perform, and then immediately moving on to another project to continue the cycle.

[frocksie]

Is that fitting near the end of the barrel a compression fitting?

[Velocity]

The fitting near the end of the barrel is actually a male adapter. This barrel was intended to be used on a coaxial, but plans changed and I decided to use this barrel on this gun. While I could probably remove the male adapter through the use of my propane torch, I don't think it really looks back and I don't want to risk messing up any of the soldered joints or leaving ugly burn marks or sticky epoxy residue.

The paintball didn't go entirely through the plastic 2-liter bottle. It pierced through the front, but it could not pierce through the back of the bottle. If I used higher pressure though (250 PSI), I bet that I could shoot a paintball all the way through.

By the way, does anyone have any suggestions for things that I could shoot at? Nothing expensive though; this gun cost enough