AR guys, why is my M4 so inaccurate?

[Rick Lee]

I did put a RRA two-stage trigger in my new build. Of course, it came with the spring reversed and RRA's website instructions sucked. Good thing I had another M4 laying around to look at. I haven't shot the new one yet, though.

[m21sniper]

A good, crisp, light pull makes all the difference in the world.

PS: I agree with checking the castle nut on the breech end of your barrel, by the way. Make sure it's tight. Same for the optics mount/rings too.

[pitargue]

You're shooting minute-of-felon. (Morrigan Consulting Home Page) Me says you're good to go.

25 meter zero is 2" low at 50.

[m21sniper]

LOL@ minute of felon.

[Eric Coffey]

As mentioned, I wouldn't expect anywhere near 1 MOA (1" @ 100 yards) accuracy with cheap ammo. Add a mil-dot scope to the equasion (even with a 1 MOA reticle), and I would expect even less. Before tearing into it, grab some decent ammo and BZO it with the iron sights. I'd only get suspicious of the rifle itself if you can't get repeatable results with the irons and decent ammo.

[m21sniper]

Agreed.

[Eric Coffey]

Originally Posted by pitargue

You're shooting minute-of-felon. (Morrigan Consulting Home Page) Me says you're good to go.

25 meter zero is 2" low at 50.

LOL. Yeah, I think that's the "quick n' dirty" BZO they teach at Gunsite here in AZ (zero @ 25M with the bigger 0-2 rear aperture). The new high-speed-low-drag method appears to be modding the rear sight to bottom out at 6/3 (on a flat-top) -4 clicks, as the new 200M setting (8/3 -2 on a fixed handle M16). Then zero (adjusting elevation w/ front sight only) with the small aperture @ 50M (POA/POI). This will give you a happy coincidence @ 200M.

[m21sniper]

We zeroed at 25m with the long range aperature IIRC. It's been so damn long now.

[Jeff Higgins]

Not to insult anyone here, but it has always struck me that the AR15 / M4 "black rifle" crowd is probably the least in touch, of the whole shooting world, with what is required for good rifle accuracy.

An AR15 can be a wonderfully accurate rifle. It used to be impossible to win a high power match with one, shooting against M1A's, but the tables have now turned. It's pretty much impossible to win unless one is shooting an AR15 these days. There are some exceedingly accurate, high grade rifles available on this platform. The varmint shooters love them, and they will keep up with many dedicated, heavy barrel bolt guns in the field.

I think these specialized rifles have led the black rifle camp to believe the AR platform is an inherently accurate one. I think many expect any rifle or carbine built on this platform to shoot well. Sorry folks, but that's just not the case. The ones that are built to over-the-course or varmint accuracy standards are a far different animal than standard commercial grade or mil-spec rifles and carbines. The requirements are entirely different.

With the autoloading rifle, one can typically have dead accurate or dead reliable. Not both. Target competitors and varmint shooters won't have anyone shooting back, so dead reliable is not an issue for them. Hell, some over-the-course guys actually use ammo that is too long to fit in the magazine, and single load them for 600 yard slow fire. They are using their AR's as single shots. Even with ammo that fits in the magazine (for 200 and 300 yard rapid or timed fire) I've seen guys have to tap the forward assist damn near every shot. Can the military or police afford this compromise in the name of accuracy? Of course not.

Minimum chambers with fire-formed brass is one key component to rifle accuracy. Autoloaders have a hard time with this combination, often failing to go fully into battery. Generous chambers with small-ish ammo (per SAAMI specs) are key to feeding reliability. Accuracy suffers a great deal in the name of reliability. In light of that, I don't think there is any problem at all with your M4, or with your shooting. You just need to dramatically lower your expectations, understanding the intended use of your little carbine.

[m21sniper]

I largely agree Jeff, as i said in an earlier post, shooting a quarter sized group at 50m is excellent accuracy for a carbine.

4-5" at 100m is too much though- something is going on there. A MILSPEC 16" carbine should be in the 2-3" range at 100 meters with either M193 or M855. If you have a 1:7 twist barrel and can effectively stabilize 77gr OTM rounds at 100m, you should expect to do even better. Perhaps as low as 1.5"

My 1:9 CAR shoots Double Tap 77gr OTM rounds into an approx .5-.6" group at 25yds. This is waaaaaaay more than enough accuracy for what any of us needs a carbine to do.

.5-.6" groups mean 25yd "hostage shots" with ease, and even at 50m, you're still going to be capable of a high level of precision. When are any of us ever going to shoot someone over 25yds, let alone 50yds away?

XM193 shoots even better in my assault spoon, with 25m groups just over .3"

That means 100yd "hostage shots" are possible (though i'd certainly want magnified optics for that).

It's a 16" carbine guys....you can't have compact size and light weight and reasonable price and still expect sniper like precision(though to 100m....you pretty much have it with a good trigger, optics and shooter)

Another thing about carbines, they kick a heck of a lot more than 20" AR's. Way more muzzle rise. And the muzzle flash is immense. And they give up several hundred feet per second of velocity, and quite a lot of energy at any range to a long barreled AR too.

For a self defense weapon, a CAR with 77gr cannelured ammo is almost impossible to beat. It's tremendous blend of compact size, light weight, high firepower, highly effective fragmenting round, low penetration of media makes it great for close range fighting....but it's not a long range weapon.

[Rick Lee]

Ok, I really need to go ammo shopping. I still wonder why I was able to shoot Noah's superlight Bushmaster carbine so well. I forget the loads, but they were from Georgia Arms and I was foolishly trying to burn through it all before I moved to AZ. I'll be using black targets and quality ammo on my next range trip.

[m21sniper]

Georgia arms is really high quality ammo i think. Noah might have trigger work done to his, who knows.

Rick i'd get 3-4 brands of ammo, the stuff you'd most consider for whatever your intended purpose is. Ie, hunting, defense, plinking, whatever.

Test it all, see which works the best. Next time at the range, try 3-4 more loads.

Rinse and repeat until you have a winner.

[Jeff Higgins]

Like you said earlier, sniper, what Rick is getting accuracy-wise from a carbine with "crap ammo" is about all that can be expected. Good quality commercial or military ammo should cut group size substantially, like down to the 2-3 MOA range. Handloads using brass fire-formed in that particular chamber will help even more, but at some risk to reliability.

"Horses for courses" is kind of what we are looking at here. One would never expect a 12 pound, 26" bull barreled bolt gun with high magnification optics to be a viable self-defense gun, or a useful entry weapon. Conversely, one should not expect a light, handy little carbine to be a 500 yard sniper weapon. Both have their place. They represent opposite ends of the long arm spectrum.

[m21sniper]

As usual, agreed.

Different tools for different jobs.

[m21sniper]

Rick your 1:9 barrel's optimum bullet weight is 69-70 grains. I'm shooting 77's in my 1:9 for effect, not for accuracy. Half inch groups at 25yds is way more than enough accuracy for CQB.