[BocaDan]

So I'm in the process of building my first AR (5.56 platform). I got the entire lower already done but I'm really really stuck on barrel lengths though. Right now the longest range in my area is 300 yards but a 600 yard will be opening up in a few months. I don't hunt/varmint etc and this rifle is not for home defense either. Basically just a range gun...

Now aesthetics be damned I just love the long 24" barrels. However I'm reading that shorter 16" one is a tad more accurate than anything longer due to stiffness. I already know 1:8 - 1:9 twist rate is the right one for my intended bullet weight along with stainless steel instead of chrome moly for accuracy. But obviously barrel length is one of the hardest decisions...

Would love some some pointers really. Thanks all!

Cheers

 

[Happysniper1]

I've built ARs with 24-26" (custom) fluted heavy bull barrels that are accurate as all heck, but VERY heavy. Forget collapsible buttstock, need to put the standard A2 stock on them with the lead weight insert just ot balance it out.

I also have a 20" light barrel configuration with which I can hit a 55-gallon drum at 1,000 yards (with no crosswind) with 62-gr FMJ bullets.

Many builders opt for a 16" M4 profile barrel, and if needed/wanted, assemble a longer barrel later on. Or the other way around.

A longer barrel, of quality make, with a free-float handguard, will be more accurate than a shorter barrel. This holds true for rifles as well as pistols.

Hope that helps.

Cheers!

 

[bhale187]

Like Happsniper said, all else being equal a longer freefloat barrel will be more accurate, and weight is a consideration. If you plan to shoot mostly prone or benched a 24" with either a standard A2 stock or an adjustable precision stock like the Magpul PRS, CAA's ARS or SRS (those run $250+)

Freefloat is key, but then I don't think I've ever seen a barrel over 20" that is not freefloat.

Also, check out the 223 wylde barrels. They maintain great 223 accuracy while still allowing you to shoot 5.56 safely.

 

[BocaDan]

Thanks guys, I forgot about the existence of heavy bull barrels to be honest. Good tips though - really appreciate it

 

[mikekj]

You really need to find the purpose of the upper first, then build it to that purpose.

You can always have multiple uppers, each with a specific purpose. ie. tactical upper (short bbl) and a long range upper (long bbl).

 

[SHOOTER13]

The weapon should fit the mission...not the other way around !

Mikekj has the point...

 

[BocaDan]

I believe I have relayed the rifle's purpose & mission in my post which is hitting paper targets at 300 to 600 yards.

 

[SHOOTER13]

Yea...I can read. I was just making the statement...and agreeing with Mikekj.

Having said that...a longer barrel is the way to go, since the longer

the bullet is in the barrel, the more accurate it will be upon leaving it !

Your twist rate is 1:9...meaning one revolution for every nine inches of barrel.

This spin serves to gyroscopically stabilize the projectile, improving its aerodynamic

stability and accuracy.

 

[shoognite]

I'd look at an SPR configuration. An 18" barrel is going to get you out to those distances pretty easily.

http://en.wikipedia.org/wiki/Mk_12_Special_Purpose_Rifle

 

[mikekj]

I believe I have relayed the rifle's purpose & mission in my post which is hitting paper targets at 300 to 600 yards.

If that range is what you want to shoot, you would do well to have a 1 in 7.7 or 1 in 8 twist bbl., that way you can stabilize heavier bullets. 75 or 80 grain bullets. They will hold the wind A LOT better than 55 or 62 grainers.

I also would not go less than 20 inches on the bbl. length due to velocity loss. 22 - 24 would be even better. Weight should not be a consideration since those ranges are not shot from the standing position. Typically prone or benched.

 

[BocaDan]

thanks once again everybody for the good tips & pointers. Cheers