AR-10 accuracy evaluation...(Lots o' targets inside)

[sidewaysil80]

18" OBR 762 accuracy, is this acceptable?

Previous ammo testing featured M118, Ruag (168gr/175gr), Federal GMM (168gr/175gr), and Black Hills. All ammo produced groups virtually identical to those below which were shot with Federal 168gr Bonded LE. Tried single loading each round, shooting groups from feed ramp, and swapping scope mounts to see if groups would tighten up. Barrels were broken in following Krieger protocol (as per recommendation) and had about 500 rounds on each gun at the time of targets shot below.

The test targets provided by manufacturer were three shot groups that were sub-moa. We have never been able to replicate consecutive sub-moa groups (except once), if sub-moa is achieved the next group will open up.Throughout those 500 rounds fired, about half a dozen .mil/.gov professionals got behind these guns and results were the same. No one was able to get consistent sub-moa groups.

Are we expecting too much and this is par for the course? If not, any ideas on what could be causing it? I am trying to avoid having to send guns back for troubleshooting if we can identify problem ourselves. But manufacturer never really said if these results were acceptable or not. Hell, I'd be happy if we could consistently get moa results.

[gunnerblue]

If I'm reading this correctly, all of the targets were shot with the same ammo (Federal 168 gr Bonded LE) but through different rifles?

Three-shot groups are statistically meaningless concerning consistent accuracy. Almost any rifle will shoot three rounds into a small cluster at some point. This is why manufacturers include such targets. Five round groups are better, but shooting ten round groups will tell you the true accuracy of the rifle. There are many threads on this site and others that go into further detail.

[tom12.7]

Agreed with the above for a few reasons. What's the MK262 reference?

[Gödel]

Barrels were broken in following Krieger protocol (as per recommendation) and had about 500 rounds on each gun at the time of targets shot below.

The test targets provided by manufacturer were three shot groups that were sub-moa.

It sounds like the test targets were fired producing small groups, and then you did a Krieger barrel break in, then you tested for accuracy.

Would it be fair to say that the rifle you got was not the same after you performed a break in? It certainly adds a factor that wasn't there when the rifle was originally factory tested.

[sidewaysil80]

If I'm reading this correctly, all of the targets were shot with the same ammo (Federal 168 gr Bonded LE) but through different rifles?

Three-shot groups are statistically meaningless concerning consistent accuracy. Almost any rifle will shoot three rounds into a small cluster at some point. This is why manufacturers include such targets. Five round groups are better, but shooting ten round groups will tell you the true accuracy of the rifle. There are many threads on this site and others that go into further detail.

Yes, well technically 8 rifles. I just posted the overlays I did on two of them. I understand three shot is meaningless and typically yields the tightest groups. My issue is as you can see, we aren't even able to equivalent three shot groups. I'm just trying to find out if most OBR's shoot 5 round groups of this size or if something is amiss.

Agreed with the above for a few reasons. What's the MK262 reference?

Sorry, had a brain fart and put that instead of M118.

It sounds like the test targets were fired producing small groups, and then you did a Krieger barrel break in, then you tested for accuracy.

Would it be fair to say that the rifle you got was not the same after you performed a break in? It certainly adds a factor that wasn't there when the rifle was originally factory tested.

That is a 100% plausible, but we broke it in following the instructions provided. All 8 rifles are producing the exact same types of groups. Even during the break in they weren't grouping well. In fact, the only time they EVER grouped well or consistently is with the photocopied test targets LaRue provided.

[Gödel]

I understand all the different takes on "accuracy". It strikes me that if I had a rifle intended for SWAT "sniping" or something like that, and it fired very tight 3 shot groups to POA but opened up after 3, that rifle might still be perfect for its intended usage. Those first couple of cold shots are the moneymakers.

If that doesn't describe your situation, pardon my philosophizing.

[gunnerblue]

No disrespect intended, but gas guns are much less forgiving than other platforms when it comes to precision. Could it be the shooters? Again, not insinuating anything- this has just been my experience

[sidewaysil80]

I understand all the different takes on "accuracy". It strikes me that if I had a rifle intended for SWAT "sniping" or something like that, and it fired very tight 3 shot groups to POA but opened up after 3, that rifle might still be perfect for its intended usage.

Three shot groups would be great and we would accept that, but they won't even do that. The majority of the time those fliers you see aren't the 4th and 5th shot, they are coming from the first three.

No disrespect intended, but gas guns are much less forgiving than other platforms when it comes to precision. Could it be the shooters? Again, not insinuating anything- this has just been my experience

That very well could be. But with my other gas guns I can shoot repeated moa or better (depending on which rifle). I can't speak for the other guys but given their resumes I believe they are very capable.

[P2000]

A few of those targets like the last pair look outstanding. Some not acceptable for a precision SA rifle whether it be due to shooter or rifle.

Sent from my XT1565 using Tapatalk

[Lefty223]

No disrespect intended, but gas guns are much less forgiving than other platforms when it comes to precision. Could it be the shooters? Again, not insinuating anything ...

With respect,I too had the same thought ...

Those groups w/ an apparent horizontal shift could be inconsistent shoulder pressure. Other 'thrown' shots, if shot off bipods, could be inconsistent pre-loading. Groups that appear to be 2 groups or clusters could be 'timing of the shot break' ... some in-between heart beats, so on it.

I'd give the same rifle & ammo to a highly experienced 'trigger time' benchrest or high power shooter and see what they can produce. FWIW I now only shoot 10-rnd groups.