M&P 15 MOE Mid length accuracy question

[Rule3]

I have the above rifle. What kind of accuracy are you guys getting with plain 55 gr grain Factory ammo? I put a little better ALG trigger in it. Not a match trigger but at least a bit smoother and a tad lighter.

The rifle has a 1:8 twist so to me 55 gr bullets are kinda light. I sighted it in at 50 yards and shoot from a V shaped sand bag, Rifle has a good Burris Scope. Seems to shoot "patterns" rather than groups. Maybe I have just used to shooting a heavy barrel Savage Bolt rifle.? I do not expect it to be one hole accuracy but it spreads out here and there probably 3-4 inches. Tried different factory ammo and I reload also, Not much different. The hand-loaded 68 grain bullets shot a little better.

I am using those Caldwell Orange Peel 4- 4" targets per sheet. It will keep them in the 4" bull but to me that isn't acceptable.

Should it be better?

Thanks

 

[BillK01]

My M&P TS with a 1:7 twist 14.5" barrel and pinned Vortex hider (for the 16" ol) averages about 1.5" - 2" groups at 50 yards with an Aimpoint Pro. My dad's Sig M400/Eotech EXPS which is closer to your M&P at 16" but with a 1:7 twist is tighter at about 1" - 1.5" give or take. Both groupings are me shooting from a Caldwell Lead Sled with PMC Bronze .223, 55gr. Both rifles have Geissele SSA triggers.

I think yours should be grouping better all things being equal.

 

[MichiganScott]

What ammunition are you using? You will not get good groups with poor ammo, although there is always an exception to every rule.

I have a 1:7 match gun that will shoot bug holes off the bench all day long at 100 yards with 52gr match bullets, so the twist is not the problem.

 

[Rule3]

Win White Box, PMC, Black Hills and several combibations of my handloads using different powders and Hornady Bullets and Win Bullets. 55 gr FMFBT

I am trying to find folks with the same SW MP AR15 to see what accuracy they get. Other rifles with other twists, triggers, and bullets are not really relevant.

 

[MichiganScott]

It is a rare rifle that shoots less than 2 MOA with 55gr FMJ bullets. The majority of those bullets are .2235" diameter or less instead of .224 like they should be. They have a large variation in weight, usually +/- 1 grain and sometimes even more, regardless of manufacturer.

Examine the exposed lead base of the bullets in a box of the 55gr FMJ components. You will see the lead on some of them is not concentric in the jacket. The jackets of these bullets are quite thick. It is much easier to manufacture concentric, balanced jackets if they are thin and open at the tip instead of the base.

I have a M&P15A and my wife has an original M&P15. Neither will shoot any 55gr FMJ bullets less than 2 MOA. They may be cheap, but I no longer use them. I buy 52gr Sierra MK bulk and use them for my basic loads instead.

All of that being said, you should still be getting less than 6-8MOA. Try a different scope just to be certain that's not the problem, and check the mount. If the 68 grain handloads still shoot patterns instead of groups, I'd contact S&W. There may be something wrong with the gun.

 

[Rule3]

Scott,

Thanks. You are getting better results with a lighter bullet?? I have been using Hornaday bullets in my loads but found a bag of Winchester 55 gr that I loaded up. I am wanting to "blame" those bullets. I just loaded several more samples of test rounds to see if it's those bullets (used the Hornadys with the same powder and charge) I will have to test those out this week. If that does not improve I am calling SW (if I can get through) will not be the first time It's hard trying to explain lack of accuracy to them. Did it with a MP 45, never could get that to be accurate.

I'll go to the range with 3-4 factory loads and some of mine and document everything.

 

[MichiganScott]

At shorter distances the lighter bullets can actually be more accurate because the heavier bullets may not have totally stabilized yet. Sometime it takes quite a distance for the yaw to disappear. I usually shoot the lighter bullets simply because there is no ballistic advantage to using heavier bullets at less than 200 yards unless your rifle prefers them. The lighter ones are cheaper and there is no such thing as over stabilization.

Google "accurate AR-15 handloads" and you will find an excellent article by Layne Simpson from Shooting Times. He list several handloads that are pretty much standard in an AR. You should be able to find one using the powder you have on hand. Just start low and work your way up.

FWIW, the standard in the industry seems to be shooting five 5-shot groups when checking out accuracy. You can probably get by with four groups because that's one box of ammo, but less than that may be viewed as the shooter's fault when contacting a manufacturer.

 

[Rule3]

I can send SW as many groups as brands of factory ammo I can find

My assorted loads of different powders and bullets I can not send them

With my Savage Varmint heavy barrel I can put them in the same hole at 50 or 100 yards. Same Hornady bullets so I am leaning towards the bullet (Winchester or the barrel on this rifle) Again, I do not expect the same accuracy as that rifle but it should be better than it is.

 

[red dragon]

I have the exact rifle in question.all stock except grip(moe+).With a Bushnell red dot at 25yds,1"and under all day off my bipod.i've only taken it out to 100yds with the same red dot and was able to shoot a 5 shot 4.5" group(hey,that's good for me).with a scope i would say it could easily shoot 1-1.5"groups at a 100yds.my group at 100 was shot with some good ol cheap PMC.at 25yds even tulammo makes 1"groups. based on my experience with it(1500+rounds),i'd say it's way more accurate than anything I'll be using it for.

 

[Rule3]

Thanks, that is what I was thinking the rifle should be able to do. It has a Burris 3.5-10 with one piece PEPR mount on it, I will do some more tests this week and if I can not get it grouping better I am gonna call SW, as the barrel may be messed up or something.

 

[red dragon]

I might try a few different optic set ups first.I've herd mixed reviews on the pepr.for me sending that barrel back would be a last,last,very last resort.how does it shoot with just your irons?has anyone else shot it and how'd they do?

 

[cyphertext]

That rifle is capable of much better accuracy than that. There are folks that don't post very often anymore, but they were getting sub MOA with the 1:8 twist Sport rifles. No BS either, they posted videos of their shooting. I would look at my scope and mount, see if anything is loose. Have you shot it without the scope, just to see what kind of group you get with the irons?

I have the Sport and shoot with a red dot. At 50 yards, I can keep 5 shots under two inches using 62 gr Silver Bear. Good enough to hit a pig behind the ear!

 

[PAPS94]

Hello,
I think this AR15 can be sub MOA with a good trigger and a good shooter.
I use m'y rifle at 200 and 300m, in Paris.
Last week : (I have the S&W trigger)
C200 target with 55g Fiocchi ammo.
In France, shooters use quality bullets like Sierra HPBT match 52 ou 53g for 200 or 300m.

 

[wild_weasel]

Ammunition quality is key to accuracy in the S&W Sport. Living in Southern California I am very limited where I can shoot so use a local 25 yard indoor range that allows high power rifles. Shooting Remington, PMC, Federal, etc I thought my rifle was pretty accurate since it shoot easily into 4 cm at 25 yards from the first to last shot hot of cold! Reloading my brass really opened my eyes to the accuracy potential of the Sport with 5R barrel. Using data from the latest Hornady manual; trimming Remington or Winchester cases to a uniform length, CCi#41 or WSR primers, 27 gr of CFE223, Hornady 55 gr FMJ-BT, easily cut groups in half without tinkering much with different loads. The same loads are very accurate in my DTI mid-length, light-weight upper mounted to an S&W lower I build up.

 

[kb18no1]

I have the above rifle. What kind of accuracy are you guys getting with plain 55 gr grain Factory ammo? I put a little better ALG trigger in it. Not a match trigger but at least a bit smoother and a tad lighter.

The rifle has a 1:8 twist so to me 55 gr bullets are kinda light. I sighted it in at 50 yards and shoot from a V shaped sand bag, Rifle has a good Burris Scope. Seems to shoot "patterns" rather than groups. Maybe I have just used to shooting a heavy barrel Savage Bolt rifle.? I do not expect it to be one hole accuracy but it spreads out here and there probably 3-4 inches. Tried different factory ammo and I reload also, Not much different. The hand-loaded 68 grain bullets shot a little better.

I am using those Caldwell Orange Peel 4- 4" targets per sheet. It will keep them in the 4" bull but to me that isn't acceptable.

Should it be better?

Thanks

Sounds like fundamentals to me. Maybe get some instructions. The rifle is plenty capable of shooting tight groups.

Get out there and shoot more. It is important to make sure you get on the rifle the exact same way every time. Also are you jerking the trigger. Lots of good info out there...google it!

Good Luck!

 

[thetalon]

With my mp-15T I can easily shoot 2" groups @ 50 yds free standing using cheap 55 grain tulammo, factory trigger and a 1:9 barrel. Shooting from a rest with a custom trigger your rifle should definetly be capable of 1-2" groups. I'm not a terrific shot either. If youre shooting >3" groups at that range and are a fairly experienced shooter you may want to try a different optic and make sure youre rifle is clean and there are no assembly issues. A badly aligned compensator might throw your shots a bit.

I had a scope issue on my savage bolt gun and the zero was bouncing all over the place every shot. Couldnt hit a pie plate consistantly at 50yds. Adjusted the scope to limits and rezeroed and it and it shoots <1" groups with russian brass all day. (50yds) Scope might be a good place to start.

 

[WR Moore]

With my Savage Varmint heavy barrel I can put them in the same hole at 50 or 100 yards. Same Hornady bullets so I am leaning towards the bullet (Winchester or the barrel on this rifle) Again, I do not expect the same accuracy as that rifle but it should be better than it is.

The trigger technique for the two rifles is entirely different. I have a dickens of a time myself when I swap back & forth between bolt gun & AR. There's a major difference between 3 1/4-3 1/2 lbs and 5 plus pounds on the factory unit.

Due to the heavier pull you must have your hand firmly in contact with the grip. I find that having the trigger touching the crease at the inner end of the first joint allows me a straight back pull. You pretty much roll the trigger rather than steadily increase the pressure.

I expect the folks with real tight groups have paid for match type triggers. If all you're going to do with the rifle is punch paper, that might be fine. However, there are reasons the mil-spec on the trigger is 5-8.5 lbs.

As others have said, check your scope mounts & ring screws.

 

[webfarmer]

I sinfully have not been able to shoot mine (same as OP's) all that much (that will change!). However, off a bench at 100 yards with an Eotech 512 and my handloads, groups are ~ 2". I find that totally acceptable. The load I tried is what I found accurate in my old SP1 and was delighted it shot well in my Magpul Mid Good luck!