Optimal AR barrel length

ranger mac

Oct 11, 2009
Disclaimer: My search skills may be limited, but I have been all over look.

I was looking for the minimum and/or optimal barrel length for a 223 AR built. I found a great article a little while back on swat/FBI ballistic testing. It showed that 308 doesn't begin to lose velocity dramatically until shorter then 20" and the 300 win mag was at 22".

I am new to an AR target concept. We have 16" barrels on ours, but that is mainly for CQB requirements.

Can I built a 16" heavy barrel varmint/target AR and still optimize the round or does the 18,20, 24" benefit from increased muzzle velocity.

I know by reading generally the shorter barrels have more rigidity, I really just want it to be a good shooter, still portable, and be able to group well at 300 yards and some work with a little more.
I just bought an LTR for longer work. THANKS FOR the help
Any barrel length you mentioned will work fine with the 223. I have a 20" , 22", 24" and a 26".
The 20" is preferred for hunting, just easier to carry.

The twist depends upon what bullet you want to shoot. If you are planning on shooting nothing bigger than 55 gr bullets I would suggest the 1 in 12 twist. If you ever want to shoot anything bigger than 55 gr bullets I would get the 1 in 8 twist. My 1 in 8 twist barrel will shoot them all well.
Hey Mac,

The 16" will certainly work, but forget about the short/stiff argument with the ARs, it doesn't apply. The FAR bigger concern here is floating the barrel. a heavier barrel is certainly stiffer than a lighter one of the same length, but for accuracy, a float tube is the real ticket, with barrel weight coming in a distant second. Over the years, I've gotten very accustomed to the standard 20" barrel of my match guns, and feel that anything much longer tends to become unwieldly for many situations. The 20" is a nice compromise. Longer barrels will gain you a little velocity, shorter barrels will cost you some. Where that trade off suits your purposes, though, is ultimately up to you.

As far as the twist rate, tha 1x8" is going to be the most versatile for you. It'll still shoot lighter bullets just beautifully, and you'll be abnle to run anything up to the 80 or 82 grain match bullets for long range.

A float tube, a good trigger and a decent barrel, and you'll be ready to run.

Hope this helps,

Kevin Thomas
Lapua USA
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