What's an acceptable group for an AR15 carbine?

[turkish]

I finally got to the range with a scope on top of my AR, with the intentions of really testing its accuracy. At first, poor groups with Remington factory rounds had me doubting the new scope/mount (RRA cantilever and $100 Bushnell 4-12x40). Next, the PMC was shooting groups half that size I was really curious. Finally some handloads were the best of what I tried -- at 100yds, all within a 3" circle. All rounds were 55gr FMJ, with a Double Star 1in7 twist, CL barrel, sand bags (about as solid a rest as you could ask for).

I was pretty disappointed. I feel I can get better with tinkering with the handloads, but the factory loads I tried were really bad. I kinda doubt the optics setup was too at fault since the different loads noticeably different.

What is a good group from an AR15 carbine? Any comments? Thanks ahead of time!

 

[JBP55]

Sub 1/2" group at 100 yards.

 

[Ritten]

With a 1:7 twist try some 62 or 69gr. rounds. My RRA will hardly hit a paperplate with 55gr mil-surplus but will shoot 5 rounds in a quarter with 69gr SMK handloads.

 

[turkish]

With a 1:7 twist try some 62 or 69gr. rounds. My RRA will hardly hit a paperplate with 55gr mil-surplus but will shoot 5 rounds in a quarter with 69gr SMK handloads.

Dang, I wondered about that. Was under the impression that the 1:7 was an upgrade over the 1:9 -- as good on the light bullets and better on the heavier ones.

 

[Ritten]

Dang, I wondered about that. Was under the impression that the 1:7 was an upgrade over the 1:9 -- as good on the light bullets and better on the heavier ones.

You should be able to shoot the 55's ok with a 1:7, but the point is that all guns are different. The barrel may just need to be shot through a bit before you see your groups settle down.

 

[senseiturtle]

I wouldn't sell the gun until the barrel's broken in. Also, always check the optics and the connections, a wobbly scope screws your groupings worse than anything else.

I have a 1:9 Olympic Arms heavy barrel, and I usually have overlapping rounds @ 50, about 1-inch @ 100. Keep in mind I'm a novice shooter, only getting started with rifles last year.

 

[KellyAsh]

Sub 1/2" group at 100 yards.

LOL, that WOULD be an acceptable group!

 

[topgunz1]

Don't forget to put the shooter into the equation too, how much rifle experience do you have shooting for groups? If this is one of your first rifles, work on technique. If you have other rifles and haven't had problems getting good groups in the past, disregard this post.

 

[KellyAsh]

Don't forget to put the shooter into the equation too, how much rifle experience do you have shooting for groups? If this is one of your first rifles, work on technique. If you have other rifles and haven't had problems getting good groups in the past, disregard this post.

He said he had the gun on bags, which takes most of the shooter out of the equation.

 

[JBP55]

LOL, that WOULD be an acceptable group!

Not only acceptable but exceptional.

 

[turkish]

Don't forget to put the shooter into the equation too, how much rifle experience do you have shooting for groups? If this is one of your first rifles, work on technique. If you have other rifles and haven't had problems getting good groups in the past, disregard this post.

I have been shooting forever, long enough to know that I need sand bags to be very proficient. The trigger pull leaves alot to be desired, but I am really confident I was doing my part.

I also agree with the post about the optics. I kind of dismissed that possibility due to some ammo performing better than others. I am, however, going to try a different scope/mount to be sure. Thanks, all.

 

[Ritten]

I have been shooting forever, long enough to know that I need sand bags to be very proficient. The trigger pull leaves alot to be desired, but I am really confident I was doing my part.

I also agree with the post about the optics. I kind of dismissed that possibility due to some ammo performing better than others. I am, however, going to try a different scope/mount to be sure. Thanks, all.

If your best groups were the last ones of the day then I'd be less likely to attribute it to scope or mounting issues, although it won't hurt to rule it out.

 

[spanky]

Sub 1/2" group at 100 yards.

I think that is beyond "acceptable."

 

[Barney88PDC]

I also agree with the post about the optics. I kind of dismissed that possibility due to some ammo performing better than others. I am, however, going to try a different scope/mount to be sure. Thanks, all.

Like Ritten said if the last group was the best that MAY rule optics out but not 100%. I just chased my own tail for about 3 months with a gun that I knew shot sub 1/2 MOA that went to shooting like crap. I had checked the rings, stock, started to try to work up a different load, cleaned the bore, contacted the rifle smith for his recommendations, nothing worked. Well last Wednesday I finally decided to pull the scope and the rings in order to beable to check the screws that hold the base on. I put the wrench on the first screw and it was not tight and neither were the other three. Well I was elated because I thought I probably found the problem. I put the rings and scope back on, rezeroed the rifle and I have my 1/2 MOA rifle back. I am a HAPPY HAPPY man. I cannot even begin to express the frustration it was not being able to figure it out. I had tried to wiggle the base and I could not detect any movement so that is why I did not check that sooner. But as always check the obvious first.

 

[thatwhichisnt]

I think that is beyond "acceptable."

Depends on the weapon.

 

[Bam Bam]

Two different AR with different twist rates and barrel weights, but @ 100 yds they shoot pretty equal with me shooting them. I average sub MOA, but depends on the weather.

20 inch Hbar barrel 1-6.5 twist with 75gr hand loads!

16 inch medium weight barrel 1-9 twist using AE .223 55gr BTHP ammo.

You should be around 1-2 MOA I would think.


Bam Bam

 

[turkish]

I realize logic should say that better groups toward the end of the day points at something other than the optics. Nevertheless, I skimped on both the base and the scope in order to get something quick (and in time for my scheduled range date). I won't have an expensive scope, but I do have certain brands I trust more than what I ended up using.

The mount is the RRA cantilever style with textured knobs for securing to the rail. If this needs to be torqued to a spec, rather than finger tight, then that could've been a problem.

One other thing, with a free float tube, does it matter if the barrel is contacting the rest? I was trying to keep the bags in contact with only the handguard, but, looking back, there certainly could have been times when the barrel was supported and not just the handguard.

 

[Barney88PDC]

If the bags were touching the barrel then yes all bets are off because that will affect the barrel harmonics. as far as the screws being hand tight it would depend on the OD of the knob (bigger the knob the more torque you could get) but I would probably put a tool (wrench / screwdriver) on it and snug it up but do not get carried away. Not sure the size of the cross bolt you have but most beefier rings have a torque spec of 65 inch pounds on the crossbolts.

 

[honestlou]

Two different AR with different twist rates and barrel weights, but @ 100 yds they shoot pretty equal with me shooting them. I average sub MOA, but depends on the weather.

20 inch Hbar barrel 1-6.5 twist with 75gr hand loads!

16 inch medium weight barrel 1-9 twist using AE .223 55gr BTHP ammo.

You should be around 1-2 MOA I would think.


Bam Bam

Nice groups, but I see you're having a little trouble finding the bulleye..

 

[thomjb]

First I am not contradicting any other posters, this is my experience. I have a few AR's, my custom, target, tricked out ones will do less than 1 inch at 100 yards with good ammo all day. The over the counter, factory models will do a couple of MOA.
The biggest thing I have learned is how getting a good trigger can shrink groups.
I have 1/7, 1/8 and 1/9 and all shoot 55g and 62g well.
YMMV.