AR accuracy

[hammAR]

My older AP4 has shot many sub MOA groups. Its been a while since I've set up to shoot groups with that barrel.

Is yours chrome lined?

Jon

I love older firearms, faster horses, and younger.......
anyhow, I have a really old Colt SP1 that still does OK for a 20" with 1 in 12 rifling.............

.

[David]

Despite all the M4geries out there, and every other kind of setup, my SP1 is still my favorite of all my ARs. You're showing your classiness, hammAR!

[macphisto]

You're showing your classiness, hammAR!

It doesn't happen often. Enjoy the taste you got.

[WastingAmmo]

to answer your question Stradawhovious, i recently picked up a DPMS sweet 16 ar (16" bull barrel and flat top).

i mounted a nice AimPoint 2.5-12x56 scope to it.

my first time actually shooting from a bench rest was just last week when i went to the range at 5 below zero..
anyhow, with my first batch of handloads(3 different bullets, 3 different powders and 2-3 different loads of each -about 15 trials with 5 shots of each)
i was amazed at an AR's accuracy.. my "bad" loads were 2.5" groups, and the good ones were .7-1" groups!!

i was shooting using a bipod and just my shoulder for rear support.. but WOW!! ar's can shoot!

i would assume with cheap ammo, still expect less than 2" groups but likely 1MOA with what your gun likes best.. with handloads.. who knows!


Side note, i just changed the barrel last night to a fluted heavy barrel for less weight, so i wonder how much that will effect things..

[hammAR]

You're showing your classiness, hammAR!

It doesn't happen often. Enjoy the taste you got.

....yep, but at least I CAN get there......even if it is rarely......

.

[hornswaggle]

I was looking to complete my AR build with a 20" A3 type upper thinking that it would be more accurate than the 16"ers but not as heavy as the 24"ers. It sounds like those 16's are pretty darn good. Anybody have any thoughts regarding the 16 vs 20? I'd mostly just use it for target shooting at 100-200 yards.

[Stradawhovious]

Quick update on my 16", tookit to the range yesterday after getting it a nice piece of glass, and all things considered I was getting 1.5" - 2" groups (about) at 100 yds with "nothin' special ammo." This is with the factory DPMS trigger, which is anything but perfect. I say that this rifle is definately MOZH* accurate.





*Minute Of Zombie Head

[jgalt]

I was looking to complete my AR build with a 20" A3 type upper thinking that it would be more accurate than the 16"ers but not as heavy as the 24"ers. It sounds like those 16's are pretty darn good. Anybody have any thoughts regarding the 16 vs 20? I'd mostly just use it for target shooting at 100-200 yards.

Accuracy is only a function of barrel length if/when you are using iron sights. If you are using any type of optic, barrel length is irrelevant. You will of course lose fps with a shorter barrel, causing corresponding effects on the ballistics of any round fired through said shorter barrel, but it won't be any less accurate per se. If you'll have an optic, and there is any chance of using it for self-defense / home-defense / hunting (i.e. maneuvering in tight spaces or carrying it around), go with a shorter barrel. If it'll only ever be fired at a range, a longer barrel won't be a problem. And if you'll never shoot it past 200 yards, barrel length really won't matter at all, as at that distance on a range, the lower fps from a shorter barrel won't make a difference.

And of course, a high quality 16" barrel is going to be much more accurate than a crappy 24" barrel 8 days a week...

Having said all that - I'm not an expert, nor do I have a heck of a lot of practical experience with this stuff. But I have been doing an awful lot of reading for multiple years on what it takes to build an accurate long-range (600-1000+ meters) rifle(*), and I'm 99% sure what I wrote is solid advice. I'm also sure I'll be corrected by those with more experience if I'm not.



(*)Lots of time and ambition - very little money!

[David]

I completely agree. At the distance you listed, it will make zero difference. Anything under 300 yards is child's play with a 16" AR, especially if the target is as big as a zombie's head. And with an optic, the sight radius (as mentioned above) is irrelevant.

[Pinnacle]

Sometimes with an AR - the shorter the bbl the more inherently accurate the rifle can be. I had the option when I built my 308 to use a 26" tube - I went with a 20" bbl - that works just fine and it is a SUB MOA rifle.

It is not the length of the bbl - it is the quality and stiffness.

[Stradawhovious]

It is not the length of the bbl - it is the quality and stiffness.

[opportunity for cheap joke forcefully ignored]

And thanks for the valuable info on this, I would have thought that the longer barrels were inherently more accurate.

The more you know, the more you grow.

[hornswaggle]

Thanks guys! That's great information and really helps. It also opens up my options a lot.

Another question that leads me to then is when adding optics would I be better off topping off an A3 type upper (flat-top) so that the line of site would be closer to the barrel (less paralax effect??) than attaching the scope on top of an A2 type carry handle? My reasoning is that the farther away the optic from the barrel the greater the elevation adjustment would be needed for the same distance from where the scope is zero'd. I'm not sure if I'm describing that the same way I'm thinking it.......

[goalie]

Thanks guys! That's great information and really helps. It also opens up my options a lot.

Another question that leads me to then is when adding optics would I be better off topping off an A3 type upper (flat-top) so that the line of site would be closer to the barrel (less paralax effect??) than attaching the scope on top of an A2 type carry handle? My reasoning is that the farther away the optic from the barrel the greater the elevation adjustment would be needed for the same distance from where the scope is zero'd. I'm not sure if I'm describing that the same way I'm thinking it.......

Optics should be mounted so that you can obtain a natural and repeatable stock-weld, especially with a traditional scope. Some of the newer red-dot type optics are much less dependent upon obtaining the same eye position and relief, but, again, a natural, repeatable stock-weld is a necessity for good results long-term.

And, as a general rule, when mounting any scope, the closer the scope is to the axis of the bore, the better.

[Belgiboy]

Thanks guys! That's great information and really helps. It also opens up my options a lot.

Another question that leads me to then is when adding optics would I be better off topping off an A3 type upper (flat-top) so that the line of site would be closer to the barrel (less paralax effect??) than attaching the scope on top of an A2 type carry handle? My reasoning is that the farther away the optic from the barrel the greater the elevation adjustment would be needed for the same distance from where the scope is zero'd. I'm not sure if I'm describing that the same way I'm thinking it.......

Optics should be mounted so that you can obtain a natural and repeatable stock-weld, especially with a traditional scope. Some of the newer red-dot type optics are much less dependent upon obtaining the same eye position and relief, but, again, a natural, repeatable stock-weld is a necessity for good results long-term.

And, as a general rule, when mounting any scope, the closer the scope is to the axis of the bore, the better.

Absolutely true. I have an A2 national match model that should be very accurate. Last year I was trying to find a really good load for it so I mounted a scope on top of the carry handle. It proved to be really tough to get a decent cheek weld to the stock, it was more of a jaw weld because of the scope sitting so far above the bore axis. My groups varied from 1"+ to freakin' embarassing and everything turned into a huge waste of time, bullets and powder. I was able to pick up a plastic cheek piece that goes over the A2 buttstock, this will line my face up with the scope a lot better. I'm starting all over again. I would love to get into service rifle shooting once I've found a good load and get rid of cheekpiece and scope.

I have a question. I was thinking of doing some of the load testing indoors at 50 yards. I'm using the usual suspects when it comes to heavy-for-caliber bullets in .223: the 69-gr and 77 gr Sierra Matchkings and the 75 gr Hornady BTHP. My barrel has a 1:8 twist. I'm a bit concerned that those long bullets will not have fully stabilized at 50 yrds, I wonder if anybody has a (semi-) informed opinion on that.