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Drill Holes in Barrel (similar to Paintball barrels) is it e

Posted: Wed Apr 04, 2007 9:58 pm
by AmYisroelChai
Okay I have the forum for over a year now and have started posting but I have yet to come across this question. Mod’s please help me here.

Will drilling holes in a barrel similarly patterned to what they do to Paintball Guns help, hinder, or be totally non-effective in the performance, accuracy, and distance of the ammo?
I hope I was clear. Here is a picture of what I mean.

And yes I have the patience to duplicate the pattern..

Heres a google image search of what I am talking about...

EDIT: Sorry for the $30 Clearence -IGNORE THAT! I pulled the image of google

Posted: Wed Apr 04, 2007 10:02 pm
by noname
It doesn't do a huge amount, except for slighty suppressing the sound and, if patterened correctly, can put a small amount of spin on the balls for better accuracy.

Posted: Wed Apr 04, 2007 10:08 pm
by paaiyan
One of the beneficial effects of the holes for a paintball gun is playing woodsball when it's cold. It allows some CO2 to escape the sides and doesnt make as much of a cloud of condensation. This is useful for when you don't want to be found. In a potato gun, I really can't see any benefit.

Posted: Wed Apr 04, 2007 10:16 pm
by pyromanic13
in paint its only for looks and noise reduction. in a spud gun (or any gun) holes will only make the gun less efficient..

Posted: Wed Apr 04, 2007 10:16 pm
by pyrogeek
Yeah, some paintball guns (like most Spyders) are running at 800 PSI, the pressure of the CO2 in the tank. And our combustions will only be making like what, 100? And (most of) our pneumatics aren't going to be safely running at anything over, maybe 200 if they are home made, or 100 or so if you are using a sprinkler valve.
The porting will probably just make you lose pressure behind the projectile, and thus velocity. But, if you have the time, and are willing to take the risk, I'd say to go for it. Do it on like a 1inch barrel though so you won't be out as much if it fails.
If you have access to a chronograph, I would love the see the data if you did this.

Posted: Wed Apr 04, 2007 10:18 pm
by paaiyan
Yea, chrono some shots using a standard barrel, then drill it and chrono it again. That'd be a good test that everyone would like to see.

Posted: Wed Apr 04, 2007 10:36 pm
by AmYisroelChai
Ok great e/o thanks for the feed back. My brother is a Master Plumber so I just raid his backyard for parts and pipes :) I only pay for sprinkler valves and my own time which is very limited (I work full time, 2 kids and law school at night)

I finish semester May 8th and I get off from work the whole summer. I will definitely let you know how it goes as I was/am planning on spending my summer building Paintball mortars, rolling cannons, landmines all for woods ball. To use over the summer.

(Anyone from So Flo here - join me in E.R. this summer :)

When I get the specs I will be happy to chart the specs using the chrono from the Paintball field.

Sorry to start the topic and not come through. I wanted to hear feed back before I started. This is what gets me through the day

Posted: Wed Apr 04, 2007 10:36 pm
by pyromanic13
wha? just use a ported and un-ported paintball barrel....I think the test is unnecessary though because this is common knowledge for most paintball players. (not trying to be an Eliteis)

Posted: Thu Apr 05, 2007 2:42 pm
by boilingleadbath
I can't think of a mechanism<sup>1</sup> by which those ported barrels would induce spin - and even then, it's not going to be enough to matter<sup>2</sup>.

That said, porting a spudgun barrel is generaly going to allow the barrel pressure to get much closer to the atmospheric pressure before the projectile leaves the barrel.
This will generally<sup>3</sup> decrease velocity by decreasing the average force on (and therefor acceleration) of the projectile, but will probably increase accuracy<sup>4</sup> by mitigating the effect of the muzzle blast<sup>5</sup>.

1) Not that that means there is no such effect.
2) Your average potato has to rotate 360<sup>o</sup> once every 40 to 200" (depending on velocity, mass, and diameter) of flight to be stable.
3) If your barrel is too long to begin with, such that the barrel pressure goes below the atmospheric pressure, it'll actually increase performance by decreasing that <i>harmful</i> pressure difference... but not as well as just making the barrel shorter.
4) I suspect that muzzle blast isn't really that much of a factor in spudgun accuracy, so this effect probably won't be terribly large in most cases. (I suspect barrel vibrations and tumbling projectiles are the main culprits)
5) This will also reduce the loudness and gun-sound-like-ness of the 'boom'.

Posted: Thu Apr 05, 2007 6:36 pm
by Scope
I have that barrel its good for a backups backup :-D
It supposidly makes the projectile leave more accuratly because there is less sudden blast as the air behind the paintball equalizes.

it deffinatly has a sound effect
thats really it tho
all my barrels have it...