barrel porting

[Ov3rmind]

Anyone remember those Ramrod barrels? Now THATS porting!

Anyway, yeah what everyone said is true. A moderately ported barrel will be less efficienct, but not horribly so.

[athomas]

Originally posted by Beefullo
So the 8" unported minimag barrel is no good???

The 8" barrel is good, just not as efficient as an 11" barrel on a mag. The level 10 may change that a bit though though. Barrel efficiency vs length varies from gun to gun depending on the air delivery behind the ball.

[aut911]

one thin i need to clear up for you guys though. If the barrel in question is ported and has the same size bore throughout then it will be less efficient then the same barrel without porting.

but the thing about most barrels is the fact that they are stepped. In other words if you inlarge the diameter of a barrel to where the bore no longer touches the ball, its as if the 16 in ported barrel is a 10 inch non ported barrel for efficiency.

my .02

aut

[Kevmaster]

or take a lapco for instance that has a 14" straight bore unported.

[aut911]

not sure but i think the velocity would be lower than with a 10 inch barrel that isnt ported. Again i am not sure due to the fact that i dont have a non ported 14" barrel around here to compare.

aut

[Star_Base_CGI]

The porting is supposed to make the gun quiter. My barrel doenst have any porting. It just has a Muzzle brake.

If you dont have any porting you just have all the air come out the end. Uts actually more effiecient to have no or little porting. POP!

[Lohman446]

However, I read this somewhere, and it made sense then.

The shorter the effective length of the barrel (the point before the first ports) - the more consistent the velocity out of it - so ported barrels are more accurate, but not because of the porting doing anything other than making the barrel effectively shorter.

[anthrakz]

I remember reading that article Tom wrote. Here's a summary of what was written. Porting has an inverse relationship with efficiency. A ball will decellerate once porting begins. But porting is not all bad. Porting in the form of a muzzle brake is beneficial. In an unported barrel, the blast of air only has one place to escape, out the tip, right behind the ball, and this creates turbulence potentially knocking the ball off course once it leaves the barrel. With a proper muzzle brake the air blast is vented out out and away from behind the ball allowing it to leave the barrel almost unscathed. A good example that I can think of it the Lapco barrels. It has porting on the last 1" of its effective barrel length and also flares out after it. Effective barrel length also depends on what output pressure your gun shoots at, because air behind the ball will lose its pressure as it the ball goes down the barrel giving the air more space to fill. After a certain point your ball will decellerate, porting or no porting, due to the pressure beginning to drop off and the friction of the barrel walls. It was said in the article that a barrel of about 8"-10" was best for most applications since most guns shoot at around 200psi give or take 50psi, this was also the part where Tom says that low pressure guns (ie. low pressure autocockers) are a myth since most guns shoot at 200psi. It was a good read, and came in handy when choosing barrels. Makes you think twice about buying that shiny $100 Boomstick over the $50 Lapco, no? I knew there was a reason I preferred my old JJ hardchromes

[gamarada717]

I remember the Ramrod barrel.....I heard it actually amplified the sound on some guns.

[jpm]

I'm pretty sure this is TK's artical on barrel efficiency. Good read. Don't believe the hype, believe the science.

[nt2004]

yeah thats the one. couldnt find it on APG's webstie though