SpudFiles

I am working on a cal .69 sniper rifle with integrated pump and a 5 rounds magasine.

GGDT told me that i would get 400 to 450 fps with 20 strokes at 22,5 kilograms of resistance on the last stroke all that with a 48 inche paintball barrel (2 x 24 inches in a cooper pipe)

Would it be worth rifling the barrel, and is it possible to do that on paintball barrels (i heard someting about ceramic and teflon in the barrels)?

With 450 fps, i bet the paintball would make a very large curve...

I would imagine rifling would cause broken balls and blowby, both of which could cause problems when you shoot the gun. Blowby simply decreases the power of the shot, and chopped balls obviously cause jams.

Demon wrote:With 450 fps, i bet the paintball would make a very large curve...

A typical 12ft/lb 0.22" airgun fires a rifled projectile with a much better ballistic coefficient at over 100 feet per second faster, and most people are hard pressed to hit a 6" square target at 50 yards.

What range did you have in mind?

jackssmirkingrevenge wrote:

Demon wrote:With 450 fps, i bet the paintball would make a very large curve...

A typical 12ft/lb 0.22" airgun fires a rifled projectile with a much better ballistic coefficient at over 100 feet per second faster, and most people are hard pressed to hit a 6" square target at 50 yards.

What range did you have in mind?

I'd be worried that the paintballs would catch in the grooves, and would rupture. I think I've seen someone try rifled barrels on a paintball forum, and it wasn't really worth doing. If you want to have increased range and accuracy, try a Tippman flatline.

roboman wrote:I'd be worried that the paintballs would catch in the grooves, and would rupture. I think I've seen someone try rifled barrels on a paintball forum, and it wasn't really worth doing.

My point was that rifled barrel or not, the combination of low velocity and relatively low density projectile means that long range accuracy is unlikely, you'll probably need this sort of sight...

look at liner barrels from smartpart that should help have u guys ever tried to break a paintball there quit strong it shouldnt rupture i have a rifle barrel also look at hammerhead barrels.

http://spreadsheets.google.com/pub?key= ... utput=html i wouldn't use paintballs if you want accuracy in the first place

With a .711 cpvc barrel, i hit 90 pourcent of the time a tree 40 cm wide at 70 feet, but the round was droping of 3-4 feets. Thats why i am looking into ways to improve fps while keeping accuracy.

What is the maximum fps to ask to a 3 gram .69 paintball before it curves out of the way? Just by thinking, to keep a straight path, the paintball has to go slow enough to drop pretty much or it will curve sideways as it as no stabilizing system and is spherical .

There is a special paintball sold that has rifled fins that gives it much greater accuracy.

I have chosen paintballs as its fun to shoot,biodegradable and i would make a integrated pump gun with a system that i may patent just to bring at anniversary along my friends cheap cal .177.

I'd look at punkworks videos they have a LOT of accuracy groupings at differnt ranges with a lit of barrels

http://www.hammerheadpaintball.com/inde ... &Itemid=18

These barrels seem pretty accurate.

turner wrote:I'd look at punkworks videos they have a LOT of accuracy groupings at differnt ranges with a lit of barrels

The ones I saw were done at 50 feet in a basement, still giving pretty large groups. Without significantly higher velocity you're not going to be able to shoot accurately at ranges beyond point blank.

http://www.skirmantas.com/wp-content/ga ... g_5941.jpg

Maybe those would wisthand 400 fps and more without curving

They would but there like 75 cents and a paintball is like 2 cents

Demon wrote:biodegradable .

MOST PAINTBALLS ARE oil based this mean there not really biodigradble look on youtube for paintball coolade test

jeremysstonedrampage wrote:My point was that rifled barrel or not, the combination of low velocity and relatively low density projectile means that long range accuracy is unlikely, you'll probably need this sort of sight.

Paintballs have a pretty horrible velocity coefficient, of about 0.98 at speeds of about 100 m/s.

...and before anyone thinks a 98% coefficient is pretty good, it translates to only having 82% of your muzzle velocity left after 10 metres, and 13% left after 100 metres.
If you're looking for a decent ranged projectile, things only start to get "reasonable" past about 99.3% (about three times more aerodynamically efficient) - this sort of coefficient is where the better air rifle pellets lie.

Anyway, to get back to the topic... I think the most optimistic estimates for a meaningful trajectory for a paintball "sniper rifle" limit results (with basic paintballs) to about 100 metres, and even that is somewhat reliant on backspin (which is obviously mutually exclusive to rifling).
Those estimates do involve the paintball clocking about 300 m/s at the muzzle however.

A better projectile is really the important thing here. My suggestion remains for paintballs with little tails made out of rings of paper - additional stability, as well as (oddly) improvements in drag.