Found a used M&P 10 Saturday on a Cabelas trip and the wife got it for me for an early birthday present. It's been setup with a Nikon M308 and mount. Got to go to the range today and sighted in and verified function. It worked great and actually surprised me. I was shooting around 3-4 inch groups at 100 yards, bench resting on bags, which is pretty good for me. What would you say would be accurate expectations for 100 yard accuracy with this rifle? I'm not looking for one hole groups, I have a bolt gun for that, just curious what it should do in an experienced persons hands.

In many respects, it would depend on a number of variables. The twist should be a 1:10, so it should shoot 150s to 180s rather accurately. The number of rounds down the barrel can have an effect, since you don't have a great idea about the throat erosion, the leade, or the rifling wear at the muzzle.

In theory, I would expect any AR10 type rifle to shoot at least 1 MOA at 100 yards. If the bullet jumps more than about 0.010", expect your groups to open up. Once you decide that your M&P 10 needs a new barrel, keep a record of how many rounds you put through the barrel. Theoretically, a 30 caliber barrel should have a barrel accuracy life of close to 5000 rounds, if the barrel is taken care of.

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What ammo were you using?
Are the scope mounts tight?

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Scope was tight. The ammo was the cheap PMC that cabelas has on sale. I know the cheap stuff won't get me far but for the first range visit and getting used to the rifle I figured it would be ok. Once I get a few more range trips under my belt I'll change to a better brand and see what it will do. I think with more practice and better ammo I could do better. I'm just trying to set realistic expectations for the gun, I'm sure it can out shoot me.

Well, you did verify function!

What weight bullet were you using in the PMC ammo? if you were shooting 147/150 gr bullets, 3 to 4" groups can be considered acceptable. If you handload, or can get a box of quality 168s, you will have a better indication of your rifle's accuracy potential.

When you are shooting, how are you supporting/resting your rifle? When you have your rifle locked in place, shoot a 5 round group. When you analyze the group, don't focus on the horizontal dispersion ... focus on the vertical dispersion. That will give you a better idea of your rifle's accuracy.

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With average ammo, you can expect 1.5MOA accuracy. Yes, even the PMC should be consistent enough to get that. With match quality ammo you can expect 1MOA or better. If you start experimenting with hand loads to get the load that best matches your gun, you can get better than .75MOA.

Put another way, 2" groups should be easily obtained at 100 yards. Getting smaller groups will take better ammo and more practice. Do lots of dry practice to get used to the trigger.

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