What Brand Bullet is the best to shoot out your AR15.

If I had an AR15 with a .22lr upper and blast reducer, I would shoot Aguila 60gr SSS ammo.

Whatever makes the smallest clover-leaf out of [b]your[/b] barrel.

I reload the 55gr Nosler Balistic-tips in mine. If the Barnes-Xs weren't so damn expensive I would shoot them exclusivly. They are solid copper wich gives them a greater balistic coeficient than lead core bullets of the same weight. This is because copper is lighter than lead and the overall length is greater.

All my recovered .30 cal Barnes' on whitetail have been perfect mushrooms and 100% retention.  

53gr Sierra HP.  This bullet has produced several five shot groups inside of .25 MOA at 100 yards with my ArmaLite National Match.

1 MOA at 100 yards is what, 29mm. So .25 MOA would be about 7mm, some pretty tough groups i say. Sure youre not pulling our leg on this one.

That isn't that hard to believe. You do know you subtract the diameter of the bullet(.224") when measuring groups?

John Feamster fired a .231" group at [b]200yds[/b] with an AR. I have seen a .002" 5-shot group at 100 with a bolt action.

Tuukka-
Neither I, or the rifle can produce the .25 MOA results consistantly.  There's too many variables (wind, operator error, etc.).  The fact is, if you work with your handloads enough you can make an AR15, especially one with a precision stainless barrel flat shoot.  

My rifle seems to like 25.0 gr. of VihtaVuori N135 with the bullet seated at 2.245 the best. In ten separate five shot group tests at 100 yards, this load averaged .558 MOA.  Three of these groups were at .25 MOA or slightly smaller.

Another .25 MOA group was shot with 26.0 gr. of Varget, with the bullet again seated at 2.245.  Ten five shot groups were also measured with this load, but averaged .680 MOA.

The last .25 MOA group I will tell you about was shot with 24.0 gr. of VihtaVuori N133 also seated at 2.245.  Eleven five shot groups were measured and averaged .667 MOA.

All groups were shot from a bench rest, using a 4-12x40mm scope.  All cartidges were loaded on a Dillon RL550B.  

So nope, I'm not pulling your leg.  I'm just reporting the success I've had in testing my handloads with the 53gr. Sierra HP.

sierra 77gr hpbt match, ss109