length of barrel

[jsmythe]

ok this maybe a stupid question, but I will put it to you anyways. How much of a noticeable difference does the barrel length from 16", 18", and 20" have on a semi auto .308? what difference does it make at all (other than length)?

[TANGO2072]

Hey J

1st off I hope you're asking this in the AR-10 ( Armalite ) cuase you have decided to get the BEST.

What differences are you reffering to ?

speaking from experience, I had a stock 20", had it cut down to 18" thanx to the guys over at ADCO.  Ballistically; if you shoot Black Hills 168g BTHP, you should be averaging 2650fps, from a 20", I chrono'd mine a couple of months ago and found to have only lost ruffly that 50fps from an average of 8-rounds fired.

My AR, kinda likes 168, but I've found she LOVES 175. I have been shooting my best groups w/ it, lately and have rezero'd for that only. I'll hold off for anything else I'd need to shoot.

So unless you're running MOUT / CQB drill, the barrel length, until you go 24+"

there's not much noticable diff.

Hope this lends some insight.

[RayGun19]

I have a 16" on mine, with an AAC muzzle brake.  I was more concerned about length, and new the range would be affected slightly over a 20" barrel.  But, as I have a long rifle for out to 1000m, I wasn't too worried about that.  If the zombies ever rise, I know I have the ballistic energy out to 4-500m with my AR10, and beyond that with the long rifle.  <thumbsup>

[survivalshop]

Look at my post ,down the page a little & you can see the difference between a 20" & 16 " in FPS.

http://308ar.com/forum/index.php/topic,447.msg7139.html#msg7139

[RayGun19]

That's not enough to even worry about!  I'm also interested that the heavier 175gn bullet did better than a 168gn bullets.  Heavier is always better (or worse for the guy on the receiving end.) LOL