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Modified Paintball Gun Barrels
Posted: Fri Nov 10, 2006 5:52 pm
by noname
About two weeks ago, I had nothing to do so I modified my paintball gun (again

). I modified the barrel because some of you might know, a Tippmann 98 Custom comes with only an 8.5" barrel when you buy it. I found out that with a few layers of electrical tape, a 3/4" coupler fits perfectly over the end of the barrel. So I got a 2 foot piece of 3/4" Sch 80, chamfered one end, and stuck it in. This thing shoots as fast as ever, never breaks paint, and has more than twice the range of the original barrel, made for about 3 bucks. I know 3/4" Sch 80 isn't as good of a fit as SDR-13.5, but I tried an SDR-13.5 barrel and do to old and swollen paintballs, none made it out of the barrel intact. I recommend this mod to anyone who is tired of having to aim your paintball gun at a 30 or 40 degree angle to try to hit enemies at long range. And the suppressor from my sniper rifle fits (too bad the gun only makes noise at the bolt anyway

) Oh well, it still looks cool, or will if I ever paint the new barrel black and red. Anyway, here's the pics.
Posted: Fri Nov 10, 2006 9:57 pm
by pyromanic13
how do you gain range when the ball should be leaveing the barrle at the same speed?
Posted: Fri Nov 10, 2006 10:02 pm
by killagorrila99
Because a longer barrel gives the air more time to exit the valve, Giving it all the power :p (I dont actually know this, Just an estimation) But it would definatley be more accurate.
Posted: Fri Nov 10, 2006 10:19 pm
by pyromanic13
why would it matter it there is more air... 300fps is 300fps.
how come it doesn't show if you've edited now?
Posted: Fri Nov 10, 2006 11:27 pm
by PVC Arsenal 17
A projectile continues accelerating as long as it is inside a barrel and some force is propelling it. (air) Once it leaves, it immediately slows down. Thus, a longer a barrel increases the velocity.
It isn't just 300 fps anymore. It's beyond that. However, then it won't be field legal.
Posted: Sat Nov 11, 2006 12:09 am
by noname
I meant "faster" as ROF, not ball speed. I'm sure it will be more than 300 fps, but I can always adjust it if needed. Longer barrels also make your tank last longer because less air is used. It will probably last like 50 shots longer than the 8.5," but that could be the difference in running out of air in the middle of a game.
Posted: Sat Nov 11, 2006 12:31 am
by pyromanic13
PVC Arsenal 17 wrote:A projectile continues accelerating as long as it is inside a barrel and some force is propelling it. (air) Once it leaves, it immediately slows down. Thus, a longer a barrel increases the velocity.
It isn't just 300 fps anymore. It's beyond that. However, then it won't be field legal.
dude, it's still leaveing the barrel at 300!fps that willl not change
Posted: Sat Nov 11, 2006 12:36 am
by iamthewalrus
longer barrels would make the gas be less efficient. with tippmanns the air used it all realeased in less then a second, no expansion or anything, just the amount released from the valve. so a longer barrel would just add more friction onto the ball without and forward force keeping it at a constant or accelerating velocity, so it would be slower leaving the barrel then it would be at the start. you would have to raise the initial velocity of the shot so the final velocity out of the barrel it 300. in normal firearms this isnt a probelm because the force driving the bullet is expanding, gun power creats an expanding pressure when ignited, and constantly pressing on the bullet keeping it at a constant or accelerating velocity. according to special ops paintball, the ideal accueracy to friction ratio barrel is 13in, less then that and u lose accuracy but less friction, so more gas efficient, but longer then that and ur more accurate but use more gas.
Posted: Sat Nov 11, 2006 9:37 am
by sgort87
Guys, he says he's getting better range. What more proof do you need?
The reason for this is the same concept as adding a larger barrel to your launcher. When you shoot a paintball, the ball is long gone before gasses are done expanding. By adding a longer barrel your ball is trapped behind expanding air for a much longer time. This means that it is pushed longer and gains a higher velocity.
Think about why all those shops have "sniper barrels" They aren't long just for accuracy. They are long for the range. The extension gives a speed boost and since the ball is less likely to slow down, in return it gains accuracy.
Posted: Sat Nov 11, 2006 10:29 am
by noname
Now I can hit a target 6" in diameter from 30 yards repeatedly pretty easily. I don't know if there's more friction but I don't care, I just needed the range.
Posted: Sat Nov 11, 2006 10:45 am
by joannaardway
sgort87 wrote:Think about why all those shops have "sniper barrels" They aren't long just for accuracy. They are long for the range. The extension gives a speed boost and since the ball is less likely to slow down, in return it gains accuracy.
The reduced muzzle blast also helps the accuracy a little I think.
What's really annoying is when a cheap hired PB gun doesn't spin the PBs very well -You'd be lucky to hit a barn door at 10 paces.
EDIT: The PB will go faster! The gas isn't instantly used up after it nudges the projectile.
There is still pressure in the barrel - there is thus still force, still acceleration, and more time to accelerate in.
Thus, more speed.
Posted: Sat Nov 11, 2006 11:05 am
by noname
Which means I can turn down the amount of gas used, shoot at a legal speed, and save more gas (which is what I've been trying to say).
Posted: Sat Nov 11, 2006 11:25 am
by schmanman
and, It comes off for easy transportation!
Posted: Tue Nov 28, 2006 5:38 pm
by th3p0p0
i just made 1 but with with 3/4'' pvc .Will that work all rite?
sch 40
Posted: Tue Nov 28, 2006 8:11 pm
by judgment_arms
Late post:
Ok, yes the velocity would be higher. (I work with pellet guns a lot, so I know this to be a fact.)
But you can turn the velocity down to 300FPS.
The longer barrel would improve accuracy to a point but if it’s not crowned then it’s all for not. Even if the round is still going at 300FPS it has traveled a longer distance in a straight line before leaving the barrel so it will travel longer in a straight line afterwords.
Silencers do nothing for a paint ball gun with a barrel that long, if it decrees anything it will be accuracy.
Your best bet would be to give it very shallow rifling, maybe only half a revolution, 1 at the most. And don’t cut the groves to deep or it would rip the paintball open.
If you want a paintball gun that shoots 300FPS and can pick the fleas off a dogs back at 500 yard, go muzzleloader use SCH40 ¾ PVC and rifle it with a rate-of-twist at 1in18, with a 36inch barrel. Wad the paintball with foam rubber to were it’s a tight seal.
If you really want a repeater make it a revolving rifle.(google “revolving carbines” and/or "cap and ball revolvers" for more info.)
I’m planning on making something of this sort in the near future.