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KaLiFORNIA
09-02-2010, 2:03 PM
I'm building a LR308 and was wondering how much I would be missing if I get a 16 in barrel. I have a "gunsmith" that tells me with a 16" I would be selling myself short. I will be using this gun for hunting, but mostly range time. I woulnt mind being able to really strech the legs out it. So should I go 16",18",20",22",24", and why.

DirtRacer151
09-02-2010, 3:12 PM
Build 2 different uppers.. its that simple!

16" = good for hunting

22"+ = much better for stretching out

Sicarius
09-02-2010, 3:30 PM
What distances are you going to be shooting. Idealy, the longer, the better for farther distances. It is all compromise. You just have to find your balance. I personally wouldn't go shorter than an 18 for a 308.
Kevin

Dhena81
09-02-2010, 3:33 PM
I think that a 20" is a good compromise.

IsaacGlass
09-02-2010, 3:38 PM
What distances are you going to be shooting. Idealy, the longer, the better for farther distances. It is all compromise. You just have to find your balance. I personally wouldn't go shorter than an 18 for a 308.
Kevin

I agreed, 18 is the minimum.

killshot44
09-02-2010, 3:45 PM
Depending on your ammo selection, the longer barrel will allow for higher velocities downrange, better for accuracy at distance.

For target shooting/matches, I'd go with 20 or 22 - but that might equate to more weight than you'd want for field hunting.

bomb_on_bus
09-02-2010, 6:56 PM
How heavy a bullet in grains should be a good starting point as the heavier bullets need a good twist rate to better stabilize the round. Usually 1-10 or 1-11.25 is the standard for most applications. Some setups run a 1-12 twist and I always look into achieving at least 2 full rotations on the bullet before it leaves the barrel so for me 20-24 inches is my rule of thumb. Since your using a semi auto setup there isnt going to be much of a change at closer ranges. But around 300-400 yards you can see some differences develop between barrel lengths. Out past 600 even more so.

I would rather have the longer barrel for when I want to go out and reach some long distance targets. Having one upper is better and cheaper then 2 unless your doing CQB and long distance shooting interchangably.

pyro3k2
09-02-2010, 7:47 PM
18 is a great all around lenght, but 20 would be better if you spend more time at the range.

joelogic
09-02-2010, 10:13 PM
Could a 14.5" AR10 make a 3moa hit at 400yds? If I was going to build one I would want it as short as possible.

nrakid88
09-03-2010, 12:22 AM
With a 16 inch barrel and 155 scenars you have at least a 600 yard gun.

Jpach
09-03-2010, 12:33 AM
With a 16 inch barrel and 155 scenars you have at least a 600 yard gun.

Even without scenars youll be good at 600......depending on your requirements.

Banging steel will be no problem at that distance and even a bit further.


I say go with 16".

You arent cutting yourself short because unlike many people on here want to believe, .308 ARs arent as easy to shoot as well as bolt guns. This means its not the best platform for long range precision stuff. Since you are going to hunt, shorter is better. If you are mostly shooting at a shooting range, then you likely arent shooting at hostage-taking zombie-elephants at 2000 yards.

This all means that you really arent missing out on anything by going with a 16" barrel. Steel plates wont care about a couple 100 fps in lost velocity. For long range, go with a bolt gun.

Jpach
09-03-2010, 12:34 AM
Could a 14.5" AR10 make a 3moa hit at 400yds? If I was going to build one I would want it as short as possible.

Hell yeah.

Just feed it ammo it likes and know how to "drive" it and you can do it no problem.

Shooting a semi is different than shooting a bolt gun

joelogic
09-03-2010, 8:15 AM
Just looking for a cool run and gun, gun. For long range I would definately let my bolt gun handle that job.

Sicarius
09-03-2010, 10:46 AM
You figure for every inch, its about 40fps difference(308). At longer distances the bullet will stay supersonic for a longer period of time. A lot of inaccuracy comes from the destablization of the bullet when it hits subsonic.
Kevin

Rekrab
09-03-2010, 10:46 AM
I've got a 16" upper on my LR-308 and I don't have any trouble shooting a decent grouping at 100 yards with irons(bear in mind I have no training and am pretty new to rifles). Shooting out to 300 with a 16" should be no problem too. While the barrel is short the .308 round has plenty of power even in that short barrel.

If you were to go with an SASS 18" upper you could probably have something a bit longer and still cut down on weight.