Home Forums Hunting & Shooting AR and Tactical Rifles ar accuracy problems

I have built an AR-15 and I had full expectation for a hell of a shooter. Problem is its really not. I thought I had all the major points in building an accurate AR covered.
I have a nice Noveske matched upper and lower.
Lilja barrel. 1:8 twist and Wylde chamber
free float hand guard.
Daniel Defense parts kit.
GGG extended rail
Zeiss conquest 3-9x40 on top.


bi-pod on the bench at 100 yards the first "break in process" and sighting in, I noticed stringing shots down with factory PMC 55gr ammo.

now using a hand load, with Sierra 69gr HPBT MK's no stringing noted, BUT now its just a more random pattern about 3is inches at 100 yd.

Tried some 62gr projectiles and got about 8 inch groups at 100 yd.

I dont' think its my shooting because I can put my 6.5x55 on the bench in the same sitting and get .75" to 1" groups pretty consistently.


The AR:
one of the things I have thought is that the barrel nut may be on too tight. When torquing on the barrel nut it was consistently hitting 68 flbs to align the gas tube hole.

I have thought maybe I need to take the barrel off and lap the receiver face a bit to true it up and decrease the torque required to align the gas tube. Thats kinda top on my mind right now


I know people talk about bedding the barrel ext. to the receiver, but my barrel ext. to receiver junction is very tight. tight enough to take a very very light tap with a rubber mallet to seat it (there is dura-kote on the barrel and ext)

I don't know if i just need to shoot some heavier bullets. they seem to do better.

Due to the Wylde chamber I can't really seat the bullets as close to the lands as I would like and still fit in the magazine.

an other thing I thought might be a problem is the headspace between the bolt and barrel extension.
I do have a "model 1" bolt carrier and bolt group ( I know I know its cheep stuff, but I had it and it is supposed to be "mill spec" and pressure treated and all that stuff. I thought it would be ok)

I need some help

I am kinda new to AR's. I have a Model 1 upper with a 8 twist barrel and its shoots outstanding. I use 70g Berger VLD's and 25 grains of Varget. Bullets are seated to fit the mag's. I build lots of custom bolt guns and this one still impresses me. I have used it to compete at 500 meters with great success. This is what it does all day long! I dont care what people say about Model 1, but I will buy another one. All I have done is accuwedge and trigger work.

very nice group there.
yeah, I really don't know what my problem is.

Im going to try some different hand loads
my best so far are my 69gr Sierra's over 25gr of IMR 4895
I hope I don't just have a super finicky barrel or setup.
I mean I still have confidence in the parts I chose.

I don't think you have a problem with the AR itself. I would look closely at the sighting system, I think that's where you'll find your problem. Barrel extension bedding is a waste of time. The barrel nut is already screwed onto the receiver, leave it. Clean the barrel thoroughly as often as you can while working up loads.

I would check and re-check the optics and mounts first.

Optics mount seems solid, but I can take out the GGG picatinny extension. and just mount rings straight to the receiver top. thats easy, and free to try.

Try the Hornady 60 gr V-Max with 26 gr of Varget , Rem 7.5, Winchester Brass. I would change scopes and shoot for a group again. If a AR won't shoot it is usually the barrel. If it don't shoot then look at the crown and make sure it is OK. One other thing you might try is let one of your buddies shoot it for a group.

I would also swap the scope out with a known shooter.

I'd check scope first.

You don't need to bed, thats for tweaking the last nth out of it.

I have no clue what bedding an extension would be.

YOu've been given the 60 vmax load, also try 69 sierras, LC case, 25 of Varget and a CCK BR4, if that doesn't shoot MOA or less there is another issue.

Do NOT rest the very nose of the handguard on the front rest, the front rest should be back close to the mag well for bench shooting an AR.

If none of the above clicks, then I'd be thinking bad barrel. Which happens from time to time.

I've personally never had luck with 4895 in the 223 in an AR... FWIW.

May also want to confirm the gas tube is centering in the key, IE not out of line and binding on the carrier, thats reported to be an accuracy killer, its why I put the barrel torque at what its supposed to be and then cut away a notch either side and grind out the hole for the tube, so it stays centered and nothing touching it. Without having to over or under torque. Though IMHO 68 foot pounds should creat no issues.

I would bet it is the bipod. Lay it on the sandbags solidly and try again.
I am having a similar issue with my .223 Bushmaster Varminter but mine is solid from the sandbags (it is a good feeling when you shoot groups like these, all 100 yards)

Top: Federal factory from Walmart. Shots 1,3,4,6 are in the red. The three fliers must have come from the Federal's powder saving line.

Bottom: Zeroing in. On the right, the initial group of assorted Remington factory (yuck!) and a couple of Berger 52 gr handloads. Center group - three Berger 52 or Sierra MK 53 gr, I mixed those up accidentally.





But, from the bipod or sticks, groups open up and the rifle strings up and to the left.

My explanation is, the action begins to cycle before the bullet leaves the barrel and with a springy rest, there is enough motion in the action to jolt the rifle and shift the point of impact.

Is this a new scope? What type of mount is it in?

The 8 inch group was this the last group of the day? Did you shoot again and get a smaller group after this group?

Do you have any TSX bullets? They like to jump.

The F class folks use bipods. BUT they won't use the standard ones, cant' think of that name now though I have more than a few in my safe.. but they use ones that don't spring and slide easy in recoil... there may be something in that. But I can't see it shooting 8 inch groups.

Cleaning the barrel will not solve 8 inch groups usually either.

Have you tried slinging it up and shooting it prone with sandbags under your forward hand? I don't know about 8" groups, but it seems that a lot of ARs just won't shoot off the bench. Usually, it's more a difference of 1.5" groups vs .75" groups.

My first guess is always the scope, I have about as much faith in scopes as I do stripper's hearts.

Then check to make sure the gas tube is aligned with the gas key by sliding the carrier back and forth. It should slide easily over the tube.

It sounds like your accuracy is getting progressively worse. That sounds like scope or maybe the gas key is getting loose.

My guess would be:
A. bad scope or mounting trouble (probably where you'll find your demon)
B. bad barrel
C. shooter got too excited about the new rifle and couldn't hold still

Terry

Interestingly enough over my years of competition, the way I tested ammo was always the service rifle on bags with a scope on the carry handle. I never once had one that was worse than about .8 moa and that I contributed to a bad barrel. Every other barrel we ever had we could get down to .5 moa or so or less.

Thats not bad for off bags IMHO, but again you need to have the front rest againts the mag well IMHO>

TC1.
the scope is new (new scope, new self built AR, never proven independently)
I hope its not a bad barrel, that would surely suck!
I would really like to think its not me as the shooter as I have NEVER! shot that poorly.

and in a re-review of the "8 inch group" It was actually 4.3 in with and 3.75 in height. 10 shot group.

I should really have known that it wasn't an 8" group because these targets are 8" square. but I thought they were my 12" square targets and I didn't measure it before, I was just guessing from memory.

None-the-less. that doesn't make it any better. a 4 1/2 group is just as bad.

Im loading up some more cartridges tonight with some different powders to experiment.

I also plan to switch out the scope with another one from one of my other rifles with known accuracy.

All the more reason to swap it out with a used "proven" scope to eliminate it as a factor.
A buddy of mine purchased a New Leopold VX-3 for his Browning BAR 30-06. He went through several boxes of handloads and even more factory ammo before he came to me and said, "here fix it". After I verified that it indeed would not shoot, I replaced the scope with a proven shooter. Just like that his groups were back to normal. Sent the scope back to Leopold for replacement and all is well. It happens, even with new scopes.

the last time I shot the AR (the session that has me fed up)

I was with a friend and he brought a particular rifle.
a model 70 Winchester 270. He says he bought it from a pawn shop real cheep, was told that it wouldn't shoot either. he put a cheep simmons on it and now that thing is a real accurate rifle. I shot it that same day as the horrible AR stuff, and we both shot 3 shot groups that were cutting into each other. (at this moment I am thinking pictures would have been much better than just typing)

anyway, short story long, I agree that I need to eliminate scope problems as the culprit.

First thing I'd do with the friends rifle is do him a HUGE favor and chit can any simmons POS before it goes TU next.

ha ha. I don't have any intention of buying a simmons.
Its what he put on it. It is doing its job. and I thought it put an even finer point on the fact that his bargain rifle, previously believed by someone that it couldn't shoot, turns out to be a hell of a shooter.