Heavy Thick Profile RRA Barrel

[amprecon]

Ok, I have a 16" LAR-6.8 Mid-Length A4 and I noticed how heavy the barrel is, when I removed the handguards I couldn't believe how thick the barrel was under the handguards. I was wondering if there are other barrels available with a thinner profile that I could install in it's place.
Not to mention, since it is a 1:10 6-groove I'd be interested in a thinner profile 5 or 3 groove with a 1:11 twist.
Any suggestions or recommendations?

 

[FlyinBryan]

that is an "hbar" profile. there are barrels made that are actually thinner under the handgaurd than they are at the front sight base/gas block, made under various names such as "gov. profile, and ultralite.

generally speaking, heavier barrels are more accurate by virtue of minimizing or controlling barrel harmonics, although this rule is not set in stone, as you will sometimes see heavy barrels that are not up to snuff, as well as an occasional lightweight that will drive tacks.

 

[amprecon]

This rifle shoots great, but it's a 1:10 SPC II 6 groove and I've been reading quite a bit about how odd numbered grooved, 1:11 or more would make it an even better shooter and also reduce the chamber pressures.
I'm just wondering if this would be even worth while doing.
My main motivation would be to get a lighter weight thinner profile barrel.
Which barrel manufacturer should I be looking at?

 

[benEzra]

Here's a thread on that question on m4carbine.net:

http://www.m4carbine.net/showthread.php?t=13456

I agree that the RRA straight-profile barrels are heavy, but they're also quite accurate (though my experience is limited to .223). You can get a lighter barrel that is as accurate, but it probably won't be cheap.

 

[Welding Rod]

Are you having problems with excessive chamber pressure?

 

[amprecon]

Thanks for the link BenEzra, informative.
I've been shooting SSA 90gr. and the 110gr. tactical loads from it and have been keeping all my spent brass and I haven't noticed anything out of the ordinary with them, so I guess I'm not having any high chamber problems.
It appears that changing barrels would also require it to be headspaced with a replacement bolt as well, the more I think about it the more it seems not worth doing.

 

[Jim Watson]

If you find that odd short heavy barrel a lot to hump around, there are shops that will turn it down to service profile for a reasonable fee.

I would not worry about the effect of one rifling groove more or less or an inch difference in twist rate for standard ammo. Shoot a lot and you can explore such ideas when you must replace a worn out barrel.

 

[amprecon]

Some good advice Jim Watson, the more I think about it the more I don't think it'd be worth the time and effort just to save a little bit of weight. It is one accurate shooter the way it is.

 

[henschman]

I'd just sell the upper (or the whole rifle) and buy one that is more to your liking, rather than going to the pain and expense of buying a new barrel and having it installed, or having your current one turned down.

I'm with you though... I wish there was a much larger selection of AR barrels in a weight that is more suited to a battle rifle that gets taken into the field. But alas, we live in a country of lazy and overweight people who only shoot rested from a bench, instead of getting into field positions. The available selection of AR barrels certainly reflects that.

As was said, look for something called a "government profile barrel" or "GI profile barrel" or "lightweight profile barrel."

And all you fatties need to get yourselves to an Appleseed and learn how to shoot from field positions!

 

[Welding Rod]

"But alas, we live in a country of lazy and overweight people who only shoot rested from a bench, instead of getting into field positions. The available selection of AR barrels certainly reflects that."


Or perhaps we live in a country of lazy and overweight people who think a HBAR carbine that weighs all of 7 and 1/2 pounds with sights is somehow too heavy to use in the field!

; )

(not taking a poke at the OP BTW)

 

[amprecon]

I was just always told that one of the greatest attributes of the M16 series of rifles was its light weight. I finally get mine, a 16" barrelled one at that, and it was a heavy bugger! Kinda felt a little cheated....

 

[okiewita40]

amprecon head over to the http://68forums.com/
Lots of great info over there. plus there are some really great sponsors that are on the site a lot. If all else fails just give constructor a call and see what he can do for you.

 

[niteowl]

I was just always told that one of the greatest attributes of the M16 series of rifles was its light weight. I finally get mine, a 16" barrelled one at that, and it was a heavy bugger! Kinda felt a little cheated....

Short of building one yourself, I think the closest thing you can buy today that mirrors the original concept of Colt's "lightweight, gas operated carbine" is their 6520 Gov't Carbine model. It has the skinny 16" barrel from breach to birdcage.

 

[Tirod]

Buying a new barrel means spending $200+ and not being able to see any difference in downrange performance without a chronograph. The lighter weight will be nice, If it's got a quad rail with any accessories, you can lose more weight by going to a tube, lo pro gas block, and MBUS.

Point being almost anything done will be in small incremental steps, no one thing will shave a pound off the front end, nor will the rifling change help start knocking down bigger game. The AR already is the lightest action around, the 6.8 is 50% more powerful than the 5.56, the differences a barrel change would make will be single number percentage improvements.

Using a reamer to open the leade to .100 would be the best bang for the buck. Beyond that, the costs increase geometrically for the small improvements. It's like jonesing for the latest Mustang because it has 15 more hp over the one you have. How much difference will it really make commuting to work, not much. You could only see it printed on a time slip.

Using a 5.56 upper and going to competitive shooting events would allow you to document a serious performance improvement, shooting isn't about the gear as much as the shooter.