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Paintball Rifle

Posted: Wed May 23, 2007 10:24 am
by ShowNoMercy
Hey I am planning on building a smaller cannon for paintballs, and I want to know your thoughts on it. I am planning on using a 1 inch non modded sprinkler valve and that is the only definate so far in the eqaution. I would like it to be used to play paintball with so I need to it to shoot .68 cal paintballs at around 350 fps. So my question is what has anyone found to be a good ratio to attain these speeds and also what is the best pipe adn size to use for accuracy? Thanks

Posted: Wed May 23, 2007 10:40 am
by Flying_Salt
Generally, homemade paintball guns are too strong to shoot at people. You may want to try a ball valve or something. That or a small chamber with low pressure.

Posted: Wed May 23, 2007 10:53 am
by Fnord
Putting a ball valve or one of those garden hose valves between the chamber and sprinkler would allow you to restrict airflow enough to get the results you want. If you are using c02 though I would ditch the ball valve and set the regulator to a lower pressure.

I'm sure playing around with the ggdt will give some ball park numbers though.

Posted: Wed May 23, 2007 11:29 am
by ShowNoMercy
Btw what is the best material for a barrel? I am looking for some accuracy here so a close fit would be the best. And does anyone have like a 4 foot section they would wanna sell?

Posted: Wed May 23, 2007 11:35 am
by iknowmy3tables
the discusion of shooting people is not allowed on this forum, but... maybe if you just hapend to want your paintball gun to shoot at around 350fps we can help

best pipe sizes for paintballs are sch80 3/4" pvc, or 3/4" cpvc
use ggdt for the calculation

Posted: Wed May 23, 2007 11:36 am
by Fnord
Well, If you dont mind pvc, 3/4" sch40 works very well, but Im guessing an aluminum barrel designed for a paintball gun is going to work better.
Not sure if they even make 4' PB barrels though.

edit @ Iknowmy3tables: I dont think pcguy will mind as long as he is trying to make a safe gun. Shooting people is what they are designed for after all (well, at least thats what they are designed for nowadays. I dont think that was always the case).

Posted: Wed May 23, 2007 11:37 am
by ShowNoMercy
Ok well I want to shoot my tree outside my house :wink: and I have been trying to put numbers into GGDT but it goes crazy and crashes. So I am not sure what that means.

Posted: Wed May 23, 2007 11:43 am
by cash68
3/4 CPVC is perfect. I built a rifle to use in paintball, you can see it here:

http://www.spudfiles.com/forums/aequita ... t7999.html

Posted: Wed May 23, 2007 11:49 am
by ShowNoMercy
I have looked at your rifle before and I am kinda basing mine off yours. What kind of accuracy are you getting though? No Bs please, the gun is nice and impressive as is. I just wanna know if I should just get a regular paintball barrel or the 3/4 cpvc.

Posted: Wed May 23, 2007 11:52 am
by Fnord
I got about 320 fps from the ggdt with a 30" barrel and a 1"x8" chamber, at only 50 psi.
This seems like a very reasonable and versatile gun to build.

whats a paintball weigh, like 4 grams?

Posted: Wed May 23, 2007 11:54 am
by ShowNoMercy
On average 3.2 grams

Merged:

Then why do people use huge barrels? If its not rifled wont it just take away from performance?

Posted: Wed May 23, 2007 12:25 pm
by Fnord
A 30 inch barrel is a good blend of power and versatility. If you start going longer it will be more cumbersome, and shorter it will probably lose accuracy. If you dont mind a bulky gun, then by all means try a 4 foot barrel. 30" was also about the ideal number for the chamber size.

Also, a rifled barrel will probably give you a noticable increase in accuracy. Thats why I suggested looking for a professionaly made aluminum barrel.

Posted: Wed May 23, 2007 1:21 pm
by ShowNoMercy
Thats what the plan is now, but I am not sure where I would get a rifled barrel at a decent price so I guess I will stick with a long paintball barrel or a cpvc one. And I think I may try a breech design for some added practicality shooting that tree out back.

Posted: Wed May 23, 2007 2:26 pm
by iknowmy3tables
longer barrels usually add power and accuracy unless the barrel is ridiculously long or the chamber is ridiculously short.

you should consider a gravity fed bolt action

Posted: Wed May 23, 2007 2:26 pm
by MrCrowley
What threads do proper paintball barrels take? To slow the FPS down you could get one of those.