When I browse the gun boards on the internet, I still see the claims by bench rest experts about how a carbine has to have the barrel free floated, preferably with a 400 dollar match stainless steel barrel. Or even more laughable. with a cold hammer forged barrel. Otherwise you are gonna be stuck with a 4 MOA or worse, gun. Last year I took a rack M4 out to 1,000 yards on a man sized target to show it could be done, but that was not the same as setting down from a rest and squeezing all the accuracy out of it I could get for pure precision.
So today I took a 6920 Colt ( M4) and slapped on my trusty Leupold 18x target scope, and grabbed some ammo to do some accuracy testing. The only thing different about this gun, is it has the SSA trigger to help with the groups and a Gunfighter Charging handle along with a standard Colt ambi safety that has no effect on its barrels accuracy. The gun still had the side sling swivel, and I even left a sling attached, and the factory hand guards. Other than the trigger and scope to help on my end, the gun had no other upgrades to the barrel. It was as it comes from Hartford. Gun was fired from a bench with front and rear bags using the Leupold 18x target scope I use for accuracy testing.
I drew a few dots and set the target out at 100 yards and got to work. Above is a 18 round group fired with M855. It is not a bad groups actually if you look at it in context. Some of the rounds obviously were not consistent with the rest, but the rest did give a group not bad at all for military ammo. I have seen M855 do better, but it is not match ammo.
Then I moved to shooting match quality ammo. The first group on the left, is 5 rounds of MK262 ammo, This is 77 grain Sierra HPBT’s. I only fired five rounds, because that’s about all I have left. I find this to be a normal group for MK262 though. Middle group is the Hornady TAP ammo, in .223 pressure loading, not the 556 NATO version. This is a ten round group. And it is normal in my experience with TAP. It is pretty good stuff but not as great and super accurate as a lot of people think. But it is nothing to sneer at by any means. Its terminal performance makes it an excellent round, especially if you get the 556 pressure stuff. Last group on right is Norma Match ammo I recently started buying and testing. Man! I did not expect to see this group. I knew it was good stuff because I knock crows out of trees at 200 yards with it all the time in a target AR15, but this was the first time I had shot it in a carbine for accuracy. I fired ten rounds of the Norma Match. It uses the same Sierra bullet as the MK262, but obviously more care goes into the making of this ammo. Norma has long been known for super high quality brass, so it should surprise no one that any ammo they make would be outstanding.
There have been probably a million accuracy tests of carbines on the web over the years, but it is always worth repeating since few actually put in the real effort to see what I plain rack grade barrel will do. You can do very good work with a factory carbine despite what you will read from internet experts, and the companies trying to sell you something. Your skill and practice are much more important than a FF tube when the gun is quality to start with. It is important to realize that rack grade does not mean just any Ar brand that looks like a plain M4 though. There is more to making a quality gun than just looking the same as another. But a proper made gun, made to last and be tough, will offer up enough accuracy for just about anyone if they dedicate themselves to becoming a real marksman, and not just a dirt clod blaster who burns up 15 rounds a second from 15 feet.