Ten Shot Group Size

[Okie_Poke]

Question: What level of precision do you experience out of your 6.5 Grendel barrel? In particular, I'm interested the size of 10-shot (or larger) groups at 100 yards (or any distance if group size expressed in MOA or MILs). Those ten shots can be shot all at once, 5 shots then barrel cool, or whatever---but all 10 at the same point of aim without ignoring any "fliers." I'm not particulalry interested in the size of your 3-shot or 5-shot groups unless you shoot several of them in a row AND correlate the different groups to the same point of aim and come up with an aggregate group size.

For various reasons, I'm currently using 10-shot groups to compare different loads and factory ammo loadings. I don't particualry want to debate the merits of that versus other load development methods in this thread---I'm just looking for data to compare to on an apples-to-apples basis.

I appreciate your experience and feedback on this. I'm trying to establish something of a baseline to compare a particular rifle against. I have quite a bit of experience with semi-precision reloading for a bolt-action rifle, but considerably less so with an AR15. I've loaded for ARs for a long time, but only relatively recently have I began shooting (local) matches with them or paying as much attention to my precision and repeatability as I do to my bolt action rifles. I want to make sure my expectations of the AR15 are realistic. Thanks in advance!

[Eggman2.0]

About a month ago I met a gentleman who competes at long distance events and he let me shoot 10 for "score" at 600 NRA target with a light variable crosswind, this was mi first time ever beyond 200.
I shot a 98 with 4x's so 2 outside 1 minute I shot a second 10 also for a 98 but with 5x's this was with 110gr Lehigh Defense match solids with 28.6gr TAC at 2.255.
I have 1 other load with the Nosler 123cc that will shoot the same @ 200 if I'm on my game.
But the rifle and ammo will preform as good or better whit my grand daughter behind it and she has less that 50 rounds rifle experience total so the combo is sound.
I'm new to both distance shooting and reloading so with sources like here and attention to detail much is possible.

[Zeneffect]

Expect 6 moa and you won't be disappointed or when you can put 20 into 1/2 then you know that barrel is a keeper.

In other words... its highly barrel and shooter dependent. Expectations may vary, and end goal is really how much do you want it will determine if you achieve it or not.

[Eggman2.0]

Looking back I believe the number of rounds I have shot working up loads has had as much to do with me shooting better as the loads I worked up do in the long run.

[LRRPF52]

This is from the lightweight Lilja 17.6” barrel shooting a hand load of 31.2gr of CFE223 under a 123gr A-MAX at 2.267” COL, using a standard AR-15 trigger before I put the LaRue MBT-2S in it:

[Okie_Poke]

About a month ago I met a gentleman who competes at long distance events and he let me shoot 10 for "score" at 600 NRA target with a light variable crosswind, this was mi first time ever beyond 200.
I shot a 98 with 4x's so 2 outside 1 minute I shot a second 10 also for a 98 but with 5x's this was with 110gr Lehigh Defense match solids with 28.6gr TAC at 2.255.
I have 1 other load with the Nosler 123cc that will shoot the same @ 200 if I'm on my game.
But the rifle and ammo will preform as good or better whit my grand daughter behind it and she has less that 50 rounds rifle experience total so the combo is sound.
I'm new to both distance shooting and reloading so with sources like here and attention to detail much is possible.

Thanks for sharing. Were you shooting on an F-Class center or a regular High Power center at 600 yards? Either way, that's nice shooting at distance in a variable wind.

[Okie_Poke]

This is from the lightweight Lilja 17.6” barrel shooting a hand load of 31.2gr of CFE223 under a 123gr A-MAX at 2.267” COL, using a standard AR-15 trigger before I put the LaRue MBT-2S in it:

Thanks for sharing. That's a pretty looking group and rifle. Are those 1-inch squares, such that the extreme spread of that group is about 1.1 or 1.2 when you include the top two, or am I looking at it wrong?

[Eggman2.0]

Thanks for sharing. Were you shooting on an F-Class center or a regular High Power center at 600 yards? Either way, that's nice shooting at distance in a variable wind.

He told me the 10 ring was 1 minuet and the X .5

[Okie_Poke]

Expect 6 moa and you won't be disappointed or when you can put 20 into 1/2 then you know that barrel is a keeper.

In other words... its highly barrel and shooter dependent. Expectations may vary, and end goal is really how much do you want it will determine if you achieve it or not.

This is kinda why I'm asking about this. I know each barrel is a law unto itself. And I understand that none of us can account for how good or bad the shooter is asking the question on the other end of the interwebs, and what's "good enough" or even "it's a shooter" for one man's purpose may be "pull the barrel and throw it away" for someone else. I'm trying to manage my own expectations here a bit as I work on load development for my Grendel AR. I'm just after honest responses from folks, whether it's "my rifle wont' put 10 shots under 2 MOA" or "my rifle will put 20 shots under 1/2 MOA." I'm just curious about the honest performance report, and from what type of barrel.

As I've detailed a bit in my dedicated barrel post, I'm experiencing more variability with how my AR shoots than I expected. I've paid quite a bit of attention to load development for my bolt action rifles over the years, but I've always just let "good enough" be good enough when loading for an AR and never really worried about it too much. Now, I'm paying more attention thant I ever have to a gas gun and I'm wondering how unusual what I'm experiencing is. For example, yesterday I had several 3 and 4 shot groups under 1/2 MOA. I had a few 5-shot groups under 1 MOA, and several more under 1 1/2 MOA. But my smallest 10-shot group was 1.64" at 100 yards. Often, it's 1 or 2 shots that get thrown vertically that throw my groups off (similar to what LRRPF52 posted but more exagerrated---my clusters aren't that tight and my 1 or 2 "fliers" are further afield). I experience a similar phenomenom with bolt rifles, just not as dramatic.

[Okie_Poke]

He told me the 10 ring was 1 minuet and the X .5

That's the F-Class center. Means your 9 ring was about 1 1/2 MOA. Good shooting in a varaible wind for sure.

[Bonas]

I usually test loads with 7 shot groups and go down to 5 shots to test against established data. I'll even use three shots for some purposes, like to check a scope adjustment.

I'd be happy with 1.5 moa 10 shot groups from an AR that will shoot .8ish 5 shot groups with some regularity.

Five shots is not statistically significant. Three tells you next to nothing about accuracy. As I wrote in your other thread, ARs are not F-class rifles and shouldn't be expected to perform anything like them. I've actually shot a very accurate AR in a mid-range prone match in the F/TR class.

Also, as I wrote before, things people post on the internet create unrealistic expectations about accuracy for ARs. There's a good reason not many people shoot 10 shot groups: They don't like what it tells them. People also post lots of one-off groups and speak in generalities that overstate accuracy.

I've shot a .457 moa 5 shot group with that AR mentioned above. I've shot plenty of sub .7 moa 5 shot groups with it. If I shoot a 1.5 moa 10 shot group with it, I wouldn't think anything was out of the ordinary.

The results you're getting are not out of line with what I would expect from the barrel you're using. I'm sure there are Monster barrels out there that shoot better, but that's a class of barrel where significant variability in accuracy should be expected from barrel to barrel. You didn't get lucky with yours. I don't think it's any more complex than that.

Edit: X-Caliber barrel, not Monster. Sorry about that.

[LRRPF52]

Thanks for sharing. That's a pretty looking group and rifle. Are those 1-inch squares, such that the extreme spread of that group is about 1.1 or 1.2 when you include the top two, or am I looking at it wrong?

Yes, 1” squares. When I shot that group, I remember the impacts that were outside of my hopes made me kind of just let go afterwards, so I emptied the mag pretty fast and the rest cut the ragged hole. With that Lilja 17.6” Wasp profile barrel, I’m confident it will shoot 10 rounds inside of 1.5”, 5rds inside of 1”, and 3rds inside of .5”, but sometimes the 3-5 rounds might be much bigger.

This is why the “Sub-MOA all-day long!” claims we often see don’t hold up to reality, even with many precision bolt guns.

Doesn’t matter much for me because I love shooting steel, and almost all of the steel targets I shoot are 2-3 MOA plates and sils, so wind call and fundamentals matter more.

[Eggman2.0]

Reading this has left me with a question that one of you might have an answer for, so normally I shoot at 200 yards weather permitting 3 times a week.
When I had the chance to shoot at 600 the 20 rounds I fired were much tighter that my normal groups were I normally shoot 5 shot groups and at 200 that
are 1.5-1.75 MOA yet at 600 3 fliers out of 20 out side the MOA ring. That don't make sense to me...unless I was just really on the ball that day.
Is there something that could help me understand what I'm doing or not doing so is it telling me that my projectile has not settled down by 200?
So many variables here that I never knew existed...

[LRRPF52]

Hornady did an in-depth discussion about all this basically saying that if your group sizes are really small, you haven’t shot enough or large enough samples.

[Zeneffect]

5 gives an idea of what is putting you on the right track.

20 gives you the beginning of the usable data statistically.

That 6 fliers in 20 shots is your group size, those aren't fliers if you didnt induce them. You need to shoot groups of 20 begin to validate your actual group.

Also... if the rifle + ammo combo is shooting around 2moa at 200, you won't be having a good time at 600. Fliers included, you will want to strive for 1 or better.


I'll take a gess here... either factory hornady black, or something with cfe223 in the 123gr class doing around 2500fps. I'd suspect if this is the case that if you reduce the charge to clean up the post barrel exit burn the groups shrink. I have enough data correlating powder burn totality and group size to avoid anything that doesn't produce a 98% or higher burnout in the barrel.