AR15 consistent grouping issue??

G

G Anderson

Member
I have a custom AR15 in 6x45,(RR Lower, 3# trigger, 22" custom barrel) that just will not group no matter what load combo I use. On the rare occasion that a good group(1/2" to 3/4") does present itself, I can never come close to duplicating it ever again. Another interesting issue with the groups is the sequence that it "throws" a round way out...it will 99% of the time throw the second shot...this is without fail. 1st shot, then second shot goes 1" to 2" right and sometimes high(every time!), third shot goes back to either touching first shot or within 1/4" to 1/2" of the first shot. This is group after group with all different powder/load combinations. Powders used have been Benchmark, H4895, 8208, Lake City and Remington brass, CCI450 and Nosler 70gr BT's primarily.
Now, I have 3 other AR15's and none of them exhibit this behavior...20 Practical AR, 223 AR and both are honest 3/4" guns with several groups under 1/2". I have a 17HMR AR and depending upon wind is an honest 1" or less and will out shoot the 6x45.
So, with this said, what could be accounting for this 6x45 AR to be grouping like this...primarily, why or what is going on that the 2nd shot is ALWAYS a flyer? This is not just one or two groups...I'm talking EVERY group...several hundred rounds of groups without fail ALWAYS throwing the second shot way out, to the right and sometimes high. Is it the gas system, barrel or barrel torque? I can't imagine a bad barrel doing something this consistent...so what could be causing this 2nd shot flyer every time? I don't have anything like this going on in my other AR's, so I am ruling out shooter error...not that I haven't buggered up a few good groups but even I couldn't be this consistent with throwing EVERY 2nd shot out like this.I have several hundred rounds now thru this AR and it doesn't seem like it is going to "come out of" this issue...I know I can send it back to the builder and get taken care of, but wanted to give it a thorough chance to "come around". Would also like to know why on the 2nd shot
confused.gif

Thanks in advance.

Gene
 
Did the upper receiver get lapped before barrel install?
Is the barrel nut torqued properly?
Make sure that there is plenty of clearance between gas block and hand guard.
Have you tried shooting it with a different optic/mount combo from one of the rifles that are confirmed shooters?
 
Originally Posted By: jk2paintworxDid the upper receiver get lapped before barrel install?
Is the barrel nut torqued properly?
Make sure that there is plenty of clearance between gas block and hand guard.
Have you tried shooting it with a different optic/mount combo from one of the rifles that are confirmed shooters?

X2

Custom mean someone put it together. You should ask them what they did?
 
I think that you have answered your own question. IF you have taken all the steps, including changing out optics and mount, and it still does it, then as Holmes said, if you have eliminated the impossible whatever remains however improbable must be the truth.

It seems to be a bad build, send it back. To do otherwise is just an exercise in futility and will simply frustrate you. Whether it's barrel torque, a bad barrel, that all sits with the builder and you shouldn't do anything about it.

As an armorer, I take great pride in the guns we send out the door. Every now and then we get one that acts up, and we encourage our clients to send them in to us so that we can get it fixed and to learn from it so that it doesn't happen again.

Good luck, please keep us posted on the progress.
 
couple things you can try, if you haven't already


1) single load - just a test of consistency to see if something goofy is happening during normal cycling.

2) if you have access to one, lock it into a gun vise like a leadsled to eliminate shooter error - or at the very least see if another shooter exhibits the same symptoms


but as others have mentioned, if youve tried all the basic tricks already, contact the builder and arrange to send it back. a custom upper should perform like one, not be a frustration point like some generic rack guns can be. its defiantly weird that it seems to only be the 2nd shot where the flyers show up and that its THAT consistent about it.
 
Originally Posted By: jk2paintworxDid the upper receiver get lapped before barrel install?
Is the barrel nut torqued properly?
Make sure that there is plenty of clearance between gas block and hand guard.
Have you tried shooting it with a different optic/mount combo from one of the rifles that are confirmed shooters?
Without going into who...the builder is a well known builder and I believe the receiver to be squared and barrel torqued properly.
Yes, I did check for gas block clearance and it is fine.
Scope has been confirmed ok.

I can't help but think it has to be a "mechanical" anomoly because of the time and again consistent 2nd shot always being out to the right and slightly higher and then the 3rd shot going right back to the 1st shot...this is consistent over 5 different bullet(s), weights etc...70 Nosler BT, 70 Sierra BK, 70 Sierra MK, 65 Vmax, 58 Vmax. I couldn't get it to be so consistent if I tried!!! It is just plain weird.

Thanks
 
Originally Posted By: willy1947Originally Posted By: jk2paintworxDid the upper receiver get lapped before barrel install?
Is the barrel nut torqued properly?
Make sure that there is plenty of clearance between gas block and hand guard.
Have you tried shooting it with a different optic/mount combo from one of the rifles that are confirmed shooters?

X2

Custom mean someone put it together. You should ask them what they did?




Spoke with builder in the beginning and we came up with several "points" to try,from reloading techniques to bench techniques...even bought different bench bags to better set the butt stock.

Thanks
 
Originally Posted By: SnowmanMoI think that you have answered your own question. IF you have taken all the steps, including changing out optics and mount, and it still does it, then as Holmes said, if you have eliminated the impossible whatever remains however improbable must be the truth.

It seems to be a bad build, send it back. To do otherwise is just an exercise in futility and will simply frustrate you. Whether it's barrel torque, a bad barrel, that all sits with the builder and you shouldn't do anything about it.

As an armorer, I take great pride in the guns we send out the door. Every now and then we get one that acts up, and we encourage our clients to send them in to us so that we can get it fixed and to learn from it so that it doesn't happen again.

Good luck, please keep us posted on the progress.

At that point now...just wanted to try every conceivable thing to rule out something wrong with the build. I always start with myself first, reloading issues/techniques, bench issues/techniques before blaming a bad rifle/barrel. I've had a few finicky rifles before and eventually got them shooting great, but nothing like this.

Thanks and I will let you know what ends up happening.
 
Originally Posted By: reloader326Sounds like a improper heat treating / stress relieving issue with the barrel, IMO.
As stated above, I'd send it back to the builder.

But does it seem plausible that if the barrel was "bad" that it would be so predictable? I would think it would be more erratic in nature than so consistent.

Thanks
 
Originally Posted By: Plant.Onecouple things you can try, if you haven't already


1) single load - just a test of consistency to see if something goofy is happening during normal cycling.

2) if you have access to one, lock it into a gun vise like a leadsled to eliminate shooter error - or at the very least see if another shooter exhibits the same symptoms


but as others have mentioned, if youve tried all the basic tricks already, contact the builder and arrange to send it back. a custom upper should perform like one, not be a frustration point like some generic rack guns can be. its defiantly weird that it seems to only be the 2nd shot where the flyers show up and that its THAT consistent about it.
Have not tried single loading, but have tried different mags and different numbers of rounds put into the mags...didn't seem to matter.
Don't have a lead sled but have had another shooter shoot it with same results. It is so predictable in doing this that like I said...I couldn't do this so consistent if I tried.
Will end up shipping back to builder to see what he can come up with.

Thanks

Thanks
 
Originally Posted By: G AndersonOriginally Posted By: SnowmanMoI think that you have answered your own question. IF you have taken all the steps, including changing out optics and mount, and it still does it, then as Holmes said, if you have eliminated the impossible whatever remains however improbable must be the truth.

It seems to be a bad build, send it back. To do otherwise is just an exercise in futility and will simply frustrate you. Whether it's barrel torque, a bad barrel, that all sits with the builder and you shouldn't do anything about it.

As an armorer, I take great pride in the guns we send out the door. Every now and then we get one that acts up, and we encourage our clients to send them in to us so that we can get it fixed and to learn from it so that it doesn't happen again.

Good luck, please keep us posted on the progress.

At that point now...just wanted to try every conceivable thing to rule out something wrong with the build. I always start with myself first, reloading issues/techniques, bench issues/techniques before blaming a bad rifle/barrel. I've had a few finicky rifles before and eventually got them shooting great, but nothing like this.

Thanks and I will let you know what ends up happening.

Yeah, that's the way it sounded. But it looks like you dotted the I's and crossed the T's, except for the single load test.
 
I was going to suggest a different mag, or loading four rounds and seeing if it's the first and third that were "fliers" but you already tried that. If I had put it together it would be coming apart, and re-done. Squared up again, re-torqued, check gas tube fit through the upper and into the bolt. But being you bought it built it should probably go back.

Did you try another lower?
 
Optic check out ok. If another is available try to be presiese and mount it. Of course rings and mounts also. Remove and reset with proper torque. Shoot some groups. My past lesson.
 
Originally Posted By: newmexkidWhy don't you give H-335 a try. It solved my problems.

H335 has been used also...same thing. Hard for me to believe that powder is the cause for the second shot ALWAYS going right and high by 1" to 2". Thanks
 
Originally Posted By: SnowmanMoOriginally Posted By: G AndersonOriginally Posted By: SnowmanMoI think that you have answered your own question. IF you have taken all the steps, including changing out optics and mount, and it still does it, then as Holmes said, if you have eliminated the impossible whatever remains however improbable must be the truth.

It seems to be a bad build, send it back. To do otherwise is just an exercise in futility and will simply frustrate you. Whether it's barrel torque, a bad barrel, that all sits with the builder and you shouldn't do anything about it.

As an armorer, I take great pride in the guns we send out the door. Every now and then we get one that acts up, and we encourage our clients to send them in to us so that we can get it fixed and to learn from it so that it doesn't happen again.

Good luck, please keep us posted on the progress.

At that point now...just wanted to try every conceivable thing to rule out something wrong with the build. I always start with myself first, reloading issues/techniques, bench issues/techniques before blaming a bad rifle/barrel. I've had a few finicky rifles before and eventually got them shooting great, but nothing like this.

Thanks and I will let you know what ends up happening.

Yeah, that's the way it sounded. But it looks like you dotted the I's and crossed the T's, except for the single load test.

I did the single load today...out of 5 groups, one did not follow the typical pattern...the other 4 did the same "2nd shot out" thing.
Just for future information, if the single load did change things...what would this conclude the problem to be and what would the ultimate solution be? Obviously, I wouldn't want a single shot AR...

Thanks
 
Originally Posted By: 204 ARI was going to suggest a different mag, or loading four rounds and seeing if it's the first and third that were "fliers" but you already tried that. If I had put it together it would be coming apart, and re-done. Squared up again, re-torqued, check gas tube fit through the upper and into the bolt. But being you bought it built it should probably go back.

Did you try another lower?

Yes, I did put it on another lower today...same issue. Shot 2 groups...one above the other...and you could transpose one group over the other...they were identical!!! There is no way I could do this consistently time after time...really a head scratcher on this one.

Thanks
 
Originally Posted By: No Off SeasonOptic check out ok. If another is available try to be presiese and mount it. Of course rings and mounts also. Remove and reset with proper torque. Shoot some groups. My past lesson.

Scopes and mounts have been changed out to verify...proven scope and mount from other rifle used on this one and scope and mount from this rifle used on other rifle...that is what I meant when I stated that the scope was OK. Several hundred rounds thru this rifle trying to figure out the problem...I would find it hard to believe that a scope and/or mount problem would be this consistent time and time again. I know anything is possible though.
The strange thing about the groups is that they are all usually shaped geometrically the same...basically like an icoscilise(spelling) triangle.

Thanks
 
Is this just throwing out the 2nd shot only? Or is it alternating right and left. I had one throwing 2 groups side by side once. Every other shot. That one turned out to be it didn't like the shoulders bumped more than .002". Wasn't sure if thats what you are saying or not.
 
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