New AR, Bad Accuracy? (UPDATE: Good Accuracy!)

[hcbr]

You mentioned you pieced it together, did you some how not torque something down right? Check your flash suppressor, does it have any abrasions or burs that could be scraping the bullet as it exits the barrel?

^^^ This, my previous build, it seem the torque wasn't what it was supposed to be, had similar results. After i had a smith tighten it down for me properly with a new barrel, bam, hell I was getting consistent hits prone with no sandbag with iron sights at 100 years at the gong's on the right side of angeles shooting range. I would make sure that happens.

Also try ammo as others have said. ANd if you didn't use a sandbag, well make sure you use one or a tripod. and try a different optic.

[Dozer94]

OP, like others have stated, try different ammo. XM855 is not known for stellar accuracy to begin with. The group size that you are getting is typical for that cartridge.
Try some FGMM 77gr and I'm pretty sure your groups will shrink. Then try other loads and find the best one that your barrel likes.

[rlewpolar]

That's exactly the types of groups I get with that exact ammo and ACOG on my Sig 516. Btw, I think a large part of it is the ACOG reticle. I use the tip of the chevron at 100 yds and it looks like I am at the exact place on the target on every shot but am I really? At 100 yds, with 4x magnification, and just a point of an arrow, really hard to tell. I've been told that some of the better shooters in the military using the ACOG are able to index the ACOG reticle with their front iron site to get repeatable hits but haven't been able to have much success with this. Going to keep trying.


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[mudshark]

try this first

With a bipod and a snapcap practice at home , before you go to the range. practice a good shoulder and cheekweld , proper trigger squeeze , and non movement after the round has been shot. only after you rule out any shooter error then change anything at all. another good idea is bring a pal and let them shoot your rifle and compare results. with the components you mentioned your rifle should produce better scores with any ammo.

[hatidua]

3-4 inches with surplus quality ammo at 100 yards is normal.

that

[mrvash]

I'm gonna go try again sometime next week. I'll be borrowing my beother's Caldwell Sled and try using some sand bags. I'm actually at Sportsman's Warehouse looking for better ammo right now, I cannot believe how expensive "match" ammo is! About $1.00-$1.25/round!

[E92335i]

Yup it's like that. Same as bolt rifles, feed them with match ammo if you want tight groups.

[hossb7]

Or shoot and get good with the GI. Dont kow why people want to changer triggers due to undesired groups when they can properly learn how to shoot.

It's been proven that changing from a GI trigger to a match trigger can improve accuracy with the same gun/shooter/ammo.

[nedro]

https://www.youtube.com/watch?v=LtcLgwoy1SI

POF Barrels are POS.

[hossb7]

I'm gonna go try again sometime next week. I'll be borrowing my beother's Caldwell Sled and try using some sand bags. I'm actually at Sportsman's Warehouse looking for better ammo right now, I cannot believe how expensive "match" ammo is! About $1.00-$1.25/round!

Might I suggest Australian Defense Industries ammo. I had the best luck with it out of my 16" carbine with ACOG when compared to a few different types of match ammo.

NOTE: I still want to try the Black Hills MK262 clone, as that's probably the best 5.56 that you can buy.


16" BCM Lightweight BFH upper with 13" KMR rail and Geissele SSA-E.
TA33-8 ACOG
Australian Outback .223 69gr SMK BTHP

[nedro]

Hornady Match is pretty damned good also, but with a bad barrel, nothing is good.

[k1dude]

What brand is your barrel?

Integrity Arms 1:8 18" melonited. I have no idea who makes their barrels for them.

[nedro]

Integrity Arms 1:8 18" melonited. I have no idea who makes their barrels for them.

Wow, Lucky me. I was looking at that same integrity arms barrel for 1/2 a year until they had a Black Hole Weaponry 1:9 18" Match barrel and BMC Gunfighter charging handle for $249 shipped.
This thing is dead nuts accurate!

[RNE228]

But with what ammo? The barrel is only one ingredient of the recipe...

Wow, Lucky me. I was looking at that same integrity arms barrel for 1/2 a year until they had a Black Hole Weaponry 1:9 18" Match barrel and BMC Gunfighter charging handle for $249 shipped.
This thing is dead nuts accurate!

[penguin0123]

Try some Hornady steel match 75gr. Bench the gun using sand bags fore and aft. Just to be sure, put witness marks on the ACOG mount.

5.56 chamber isn't optimal for accuracy because of the long leade. And the XM855 isn't match grade ammo either. 4 MOA is perfectly believable.