Lightest weight, yet repeatably accurate AR-15 upper?

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Orion8472

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I'm wanting to get some input on what would be the lightest weight upper for the AR-15 that doesn't sacrifice a repeatable accuracy. I'm not talking about rapid shooting, but one set up with a scope. Precision type shooting, probably one shot every 2-3 seconds for a magazine or two worth of ammo.

Probably some sort of free floated handguard is best to take any outside influence off the barrel.

What do you think? If you have a suggestion AND are able to post a picture for reference, I would appreciate your input. Thanks!
 
You really have to decide what matters more, accuracy or weight.

That said, I think a 14.5-16" midlength superlight barrel upper from BCM might fit the bill...
 
Home built upper, LW 16-inch Colt 1:9 "unfloated" barrel, 4X scope, Colt lower w/ match trigger, from a bench will shoot five Sierra 52gr handloads into .75"-1.0" @100yds.

This from an old fogey wearing glasses and fading eyesight. :cool:

Never tried emptying the mag.

Good luck.

M
 
So you want an upper that will hold it's poi and most of its accuracy over the course of 40 to 60 rounds within a few minutes? You going to want a GOOD barrel. Barrels that I've tried that performed very well when very hot include those of Krieger, Bravo Company's SS410 line and the barrels from Superior Barrels. Although I haven't tried them for your stated purpose, I wouldn't be at all surprised if Noveske and Centurion M4 type barrels were also capable.

Many barrels will shoot MOA or even sub MOA under ideal conditions, like taking a shot and waiting 15 miuntes before taking the next. What sets a good barrel aside for a run of the mill barrel is how it behaves under less than ideal conditions. The downside is that you can get a solid wilson varmint barrel for a couple hundred bucks. A Krieger will set you back $500. The BCM about $300.

In any case, the last BCM barrel I had was the SS410 16". That barrel would consistently shoot 1 to 1.25" 20 round groups at 100 yards in a minute to a minute and a half. This barrel is pretty much a standard profile. Not heavy, but not light either. If I remember that rig, with a UBR stock and Nightforce 2.5-10X32 and mount came in right at 10lbs.
 
Do I actually NEED a "free float handguard"? I am not expecting sub MOA, but 1" at 100 yards is plenty. As stated in the OP, it is believed that for the best accuracy you would need a free floating handguard. If the advantage is only minimal, I wonder if it is worth it.

Also, when a barrel heats up, how much difference in groupings are we talking about?
 
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Floating "helps" in theory and sometimes in practice. :rolleyes: Don't have any actual data to give you, but the aforementioned CAR-15 will still group into 2-3 inches when good and hot. The good thing about a pencil-thin barrel, it cools down quickly, too.

If your goal is to shoot "bug-hole" groups at a prolonged rate-of-fire, the stiffer, heavier, longer (within reason) the barrel is, the better. And yes, I would probably float it, just for good measure. "Need" to free-float? Don't think so.

M
 
Yes, a long and heavy barrel would tend to produce better results at accuracy than a thin barrel, but I'm hoping to find the best inbetween, . . . something that isn't so heavy that it would wear you down to carry it for a part of the day, yet still stiff enough that it would be able to hold a fairly decent grouping.
 
Orion, at what distances are you talking about shooting? If you know what distances you will be shooting too, then you have a rough estimate of the velocity you'll need leaving the muzzle so that the bullet will remain supersonic out to the maximum range that you will be shooting. I only shoot my ARs out to around 300 yards tops, so I go with short barrels. A short barrel will be more accurate for a longer string of fire than a longer barrel with a like profile. The longer a barrel is, the fatter it needs to be to retain rigidity.

Although I'm shooting an 18" build right now, my favorite was the 16" BCM SS410 rig. It was light for what it was and very accurate. A longer barrel will not get you more accuracy. What it will get you is more velocity so that the bullet will remain supersonic for longer distances.
 
Whatever barrel mentioned that is selected, the rest of the "light" comes down to the upper and sight. Delete the FA, use a lopro gas block, and forget about BUIS.

Run a GI charging handle, and consider if a comp is even needed, because if you use rifle length buffers and tubes, you can smooth the recoil reaction enough they aren't needed. Violent cycling is avoided with midlength or even intermediate gas. Avoid a quad rail, use the lightest carbon fiber tube, and don't pick the conventional bipods.

A carbon 15 upper might be another choice.
 
Id suggest looking at Noveske. The N4 barrel is accurate, rigid and weighs the same as a GI profile barrel.

Or step up to the stainless barrels for more accuracy but also a little more weight.
 
Yes, a long and heavy barrel would tend to produce better results at accuracy than a thin barrel, but I'm hoping to find the best inbetween, . . . something that isn't so heavy that it would wear you down to carry it for a part of the day, yet still stiff enough that it would be able to hold a fairly decent grouping.

You might take a look at this:

http://www.bravocompanyusa.com/BCM-...ver-Daniel-Defense-p/bcm-urg-mid-16 ddl12.htm

Or, for just a little more, you can get a cold hammer forged barrel:

http://www.bravocompanyusa.com/BCM-...eceiver-Daniel-p/bcm-urg-mid-16 bfh ddl12.htm

Or, for just a little bit more, the stainless barrel with 1/8 twist:

http://www.bravocompanyusa.com/BCM-...eceiver-Group-p/bcm-urg-mid16 ss410 ddl12.htm


Note that all of these are mid length gas systems. I suggest those for the lighter recoil pulse. The stainless will be slightly heavier. If you don't like the stainless color, you can get the same barrel with ion-bond black.
 
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Thanks for the continued postings.

My current setup is a 19" full length heavy barrel with a free float handguard, . . . Scope on a flattop a DPMS thick upper. Currently, I am only able to shoot at 100 yard ranges, but would like to shoot 300-400 max.
 
Don't forget to get a good trigger. 'Makes one heck of a difference;especially for off hand shooting.
 
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