Most accurate 5.56 round

[Metal Mike55]

I've got a Sig Sauer 516 and I'm only get 4-5 inch groups with it at 50 yards. I've shot federal 55gr. 5.56 fmj. Hornady superformance match bullets 72 gr. 5.56 hollow points and didn't get as good a group as the federals. I've shot Winchester pdx1 223 defenders and got the best group out of them(still not very good) but I'm looking for a 5.56 or .223 round with around 60-70 gr. lead and more powder than the defenders, they're too slow. I'm open to reloads, I've got all the stuff for it.

[mkmckinley]

Even with shitty ammo you should be getting no more than about 4" groups at 100m. Are you using irons or some kind of optic? Are you an experienced shooter? Are you sure it's the gun and not you?

To answer your question Black Hills 77gr is kind of a baseline for "good" factory ammo.

[Iraqgunz]

Have you considered the possibility of operator error or some issue with your weapon? Loose barrel, scope mount, etc...

[munch520]

FWIW Superformance shot like dog shit out of my MK12. Southwest Ammunition has some nice 77gr.

ETA: good point, I'd diagnose software (then hardware) before worrying about ammo.

[Failure2Stop]

What experience do you have with rifle shooting?


Typos brought to you via Tapatalk and autocorrect.

[callen3615]

Ive never shot groups with my bcm, but I did a few times with my AA upper to see if piston sucked with accuracy. Even with a red dot and xm193 my AA mid would shoot 1/4 inch groups at 50yds consistently, id assume my bcm is about the same.

Id suspect operator error or this rifle has some big problems, ie headspace, or bad crown.

[juliomorris]

While you could have a lemon, I'm betting on operator error. WHat I would do is find someone that is an experienced shooter and let them give it a try.

While reloads can be more accurate you should still be getting better than 4 inch groups at 50 yards even with crappy ammo. The ammo you have listed is not crappy and I would expect 1/2" to no more than 1 " groups at 50 yards.

[Fidalgoman]

Accuracy can depend on a lot of things mechanical. For instance the dimensions of your chamber vs. your ammunition. Also short light bullets can have a bit more space in the throat to the lands than longer heavier bullets. Not all bullets are created equal. I often Use PMC .223, 55 gr and the spread at a hundred meters is about four or five inches. Granted it's usually a little gusty where I shoot. If using match grade ammo it gets considerably tighter.

[Metal Mike55]

I've had my brother shoot a group and my friend shoot a group. My brother is an expert shot. We all three shot similar groups. I have an eotech 517 and I've used it since I've had the gun and would most of the time put two holes touching and then the gun threw the 3rd bullet a few inches left, but I have noticed better groups with it. Then I've got a swift 4-12-50 scope with a nc star quick detatch scope mount but with that at 50 yards it shot 2 shots 1 inch apart and would throw the third one 3-4 inches right. It did the same pattern with all the ammo. All the shooting was using a gun vice. All three of us are very experienced shooters.

[Koshinn]

nc star quick detatch scope mount

That looks like it could be the problem. Also make sure your scope is mounted properly, regardless of the mount.

[Iraqgunz]

Get rid of the NC Star garbage and shoot 5 or 10 round groups. You have to eliminate the silly factor first.


I've had my brother shoot a group and my friend shoot a group. My brother is an expert shot. We all three shot similar groups. I have an eotech 517 and I've used it since I've had the gun and would most of the time put two holes touching and then the gun threw the 3rd bullet a few inches left, but I have noticed better groups with it. Then I've got a swift 4-12-50 scope with a nc star quick detatch scope mount but with that at 50 yards it shot 2 shots 1 inch apart and would throw the third one 3-4 inches right. It did the same pattern with all the ammo. All the shooting was using a gun vice. All three of us are very experienced shooters.

[Pappabear]

What kind of barrel is it? And what profile. My wild guess is you have an over bored barrel. Its too big, like its almost shooting a shotgun.

I had a similar experience with a bolt gun.

Cheap skinny barrel?

55grain hornandy varmint is very accurate, try it.

[Metal Mike55]

Well I'll try some shots with the federal ammo with a new scope mount and see the grouping in the morning but along the lines of ammo. I think I'll try some of my brothers custom loads. He shot 4 shots all into one hole with a Thompson center encore .223 28" barrel. The load was 25 gr. benchmark powder, 55 gr. nosler ballistic tip. C.o.l. 2.76. If anyone wants too try it out.

[bp7178]

A COL of 2.76" with a 55 gr. ballistic tip bullet?

Who would even want to try that with an AR15?

You need to buy some Gold Medal Match and see how that groups, or even better, have someone else who can shoot try out the rifle in question.

There really is a lack of information about your setup, as it relates to both the rifle and shooting posistion.

There can be a lot of fatigue introduced when shooting 10 round groups, especially if you are paced by your particular range due to when they call cease fires.

I would suggest firing 5 round groups, and averaging 4 together.

[Metal Mike55]

The barrel is a factor sig barrel mil spec m4 profile barrel, 1in7 twist. I'm going to ditch the nc star mount and try again. And yes you will probably have to change the length load I mentioned it's not a very big deal. I'm gonna try to neck them down to factory length or to fit a pmag.

[texasgunhand]

I dont think the barrel is the problem1/7 is fine. But that nc star stuff is. Prob. be better off with the iron sights.

[bp7178]

Changing the length of the cartridge is a huge deal. The Hornady manual lists the 55 gr. VMAX with a COL of 2.250" and having a MAX charge of 24.5 gr of Benchmark.

You are over that by .21" and .5 gr of powder.

You don't "neck them down to factory length".

I don't want to be a dick, but you don't seem to have a commanding knowledge here. I really suggest you get some decent factory ammunition and have someone else shoot the rifle w/o the NC star stuff.

Don't use a gun vise. You'd be better off shooting off of a soft surface. Try a backpack on the front loaded with soft goods, and a sock filled with sand/dirt/fine gravel etc as a rear rest.

[Metal Mike55]

He necked the bullets out to his Lange and tried a federal 5.56, it just hit the Lange of his gun. I'm not sure what the length of the federals is. I'm still trying to find the best loads to put through it but ill be sure to get out my sand bags and backpack for tomorrow. I'll get a good grouping out of it somehow.

[Metal Mike55]

I'm sorry for calling it necking, it's just force of habit.

[polymorpheous]

I don't know what to make of this thread.
Your reloads are way outta wack if not down right dangerous.
The Chinese scope mount isn't even fit for airsoft.
You claim .25" groups at 50yrds with a red dot. (With a .224" projectile no less.)

Like I said, I don't know what to make of this.

[Metal Mike55]

Don't be a dick.