Venturi vs. 12in

[Igotu]

Me and my friend were arguing today on what would be more efficient barrel the 8in venturi or a regular 12in. I was saying the venturi would be because its shorter and he thinks a regular 12 inch would be because it has more time to get up to speed and the venturi has to much porting. So what do you brainacs think.

[ZapTheMad]

http://www.automags.org/resource/tech/tomstech/01_barrel_eff.shtml

[Igotu]

So if i got a venturi barrel it be like a 4in barrel and his 12in would be like an 8in, the venturi would be more efective then because quoted=

Under some circumstances there is a good reason to use a short effective length barrel. Short barrels cut off the acceleration abruptly by venting and this has the effect of tightening up the shot to shot velocity variation. If you need this at the expense of efficiency then go ahead. Tighter velocity control usually translates into some improvement in accuracy due to better consistency.
Im kinda confused by this but the link helped somewhat thanks.

[Igotu]

The origonal dispute between Igotu and me was about gas efficiency. We got it worked out....since the venturi only has about 4 inches of unported barrel from what I can see it is less efficient than a 12 inch with 7-8 inches of unported barrel.
Scrumpy

EDIT: Crap, IGOTU is still logged in on my computer, so sorry about that one guys - Scrumpy

[scrumpy]

Here we go, i'm all logged in now.

The origonal dispute between Igotu and me was about gas efficiency. We got it worked out....since the venturi only has about 4 inches of unported barrel from what I can see it is less efficient than a 12 inch with 7-8 inches of unported barrel.
Scrumpy

EDIT: Crap, IGOTU is still logged in on my computer, so sorry about that one guys - Scrumpy

[athomas]

On a level 7 mag, the optimum length of unported barrel is about 10 - 11 inches. Less than that or more than that will affect efficiency. A level 10 bolt setup changes those parameters but the statistics are unpublished yet.

Based on the level 7 setup, the regular 12" barel with 7 - 8" of unported barrel would be more efficient that the ventury barrel with only 4" of unported length. The ventury barrel needs a greater burst of gas to get the ball up to speed in a shorter distance before the pressure is released out the ports.