Home Forums Hunting & Shooting AR and Tactical Rifles Want to build a 1/2 MOA AR

Buy a good barrel (but in 1:8 or 1:7 twist) and you'll meet your 1/2 moa goal easily and be able to run to 600 with heavier bullets.

This is the right answer IMO....

1/2 MOA, but unlikely to be an honest 1/2 MOA

Maybe for 3 shots. Some of these guys need to clarify.

Laughin'n here..........................they grow on trees; everybody's got one, don'tcha know.

Can you shoot 10 shots into 1/2 MOA, everyday, all day?

MM

Glen Zeidker (sp?) wrote a series of articles in Guns magazine a few years ago on building competition AR’s. An honest half MOA AR to shoot at 600 yards isn’t built by accident. His basic recommendations were to float a good barrel and develop good loads. I believe the articles were excerpts from a book he wrote. He passed away a couple years ago unfortunately.

reading through some of this again I'll just make one comment here. a half MOA gun at 100 or 200 yards is much easier to obtain than a half minute gun at 6 or 800 yards.. not to mention the human skill to do so even if the gun is capable..

The OP is talking about shots out to 600 possibly, but more like 300 yards. Again, is this 1/2 moa for 3 shots, 5 shots or 10 shots?

😳

😆😆😆

OK, let's take the 600 yards out of the equation, let's stick with 300 yards and closer, 5 shot groups.

Though I will most likely shot 10 shot groups because I sometimes get anal about this stuff. I have with some of my Bolt action rifles shot 1/2 MOA at 300 (at times) but struggle trying to shoot 1 MOA at 600. Never shot all X's or cleaned it, so guess I have to admit shooting >1 MOA at 600 with my FTR setups. Those were with reload match ammo with basically target rifles. I used to shoot FTR at St. Louis Benchrest club for a brief time.

Again, 1/2" is a goal, 3/4" more probable, 1MOA most likely. Just guessing

Only thing that changes is some bullet choices and barrel twist. I'd still use a 1/9, minimum.

I shot a little yesterday, I know these are 5 shot groups, will shoot some 10's when it isn't so windy.

Larue 16" Upper, Rock river lower, CMC trigger, 1" squares on target, 100 yards


6 groups, including bottom left, going to try a 10 shot with the 25.5 gr load

will try the 23.2 gr load also

Ok, if you're really serious about it & let's assume from what you've posted that you are an above average shooter, her are my baseline suggestions, FWIW.

Assuming that you are not planning to do a superlight weight gun..............different animal in the hardware if you are.

I would totally scrap the idea of like bullets & slow twists; 69 & 77 grain bullets are far more stable past 300 yards that the light bullets are, Sierra SMK, TMK, Berger 77's are top choice's as are Nosler RDF's. Nosler CC's & Hornady's, IME, can be good, but don't always provide the same consistency as the others I mentioned.

I've had very good luck with Rock Creek barrels via Craddock Precision, fluted, SPR configuration, 8" twist or try to get a 7" or even a 7.7" twist, either 16" or 18". If you want to step up to a Bartlien or a Krieger barrel, it MAYBE marginally better than the Rock cut barrel, but that's highly debatable at more cost.

I've had more than one discussion about it with Paul Craddock & he tells me that there is no difference in accuracy that he can tell between Rock button rifled barrels & cut, except life & the button barrel doesn't require the break-in that the cut barrel does to achieve full potential. This matches my experience as well after trying the Rock button barrels as well. The price difference between the cut & buttoned barrels is significant.

Or get something from Compass lake; they have plenty of choices of blanks too from Bartlien, Douglas & Criterion.......... not sure if they have Krieger or not. I have one Krieger & it's under MOA.

Or if you want to step down in cost, get a White Oak barrel; plenty good, just maybe a tad short of the above barrels, IMO...............I have both. You will likely not go wrong with a White Oak Wilson blank.

V-7 barrels are reported to be outstanding too by some I've had contact with that have them but I don't own any so take it FWIW.

JP Rifles barrels are beyond good........& they come with a matched bolt, which never hurts anything. The one & only that I had was a hammer; they are relatively expensive but not crazy as they include a premium bolt in the price.

I would use an adjustable gas block in any case; SLR is my choice, but there are other that work just fine.

Although some say it doesn't really matter, I say for an ultra-accurate build, use a stiffer, heavier walled upper receiver; Cross Machine Tool, SanTan & Vltor MUR are my top choices & I've used all 3............can't go wrong with any, but likely you will need to epoxy the barrel extension into any given receiver, but I have had SanTan's that needed (preferred) thermal fitting. Or step down to a BCM upper that by design, will need thermal fitting; they are straight & concentrically true, but thinner walled.............I've used quite a few. Mega's (now ZEV) are good it you can find them.

No matter which upper, I lap the face; it takes 10 minutes & makes me feel better knowing it's straight & will have full contact with the barrel extension.

Then choose a handguard that has a long(er) barrel nut for strength of connection; Geiselle & SLR excel & are fairly light & expensive; the White Oak rails are great, have a long steel barrel nut & are heavy as the rail is heavy walled & they need a special & expensive tool for installation. (If you were to go that route, I will lend you the tool) But they are rigid & priced very well.

BCM rails are fine for run of the mill builds, but not my 1st choice for a premium accuracy build.

You will need a good stock as well that provides a solid & repeatable cheek weld..........I like SOPMOD designs as a reasonable compromise from a size & weight standpoint, but Magpul PRS stocks are probably king of the hill, but heaaaaaaavy. UBR's are also good & you can always add a pad if necessary to any stock to get the cheek weld where it fits best.

Also use a high quality buffer tube so as to get a snug fir with no looseness to they stock.

Buy the best trigger you can pay for, whether you like 2 stage or single stage...............it can make or break your accuracy & consistency. Plenty of great triggers today. For me a Geiselle SSA-E works fine, everyone has there preference, triggers are not a place to skimp.

MM

Great post and suggestions.

Looking pretty good. When you shoot those 10 shot groups, do us a favor and shoot them like we did in the black rifle challenge. There's less clutter with 2 groups on one sheet of paper. I wish I had a 1/2 moa AR 15, but am pretty happy with 3/4 or so moa for 10 shots. I believe the best I did was something like .69 moa in that shoot, but pretty much proved to myself that all of my AR's are moa/sub moa shooters at least and that is pretty good for an AR. I think with a Krieger and a heavier upper receiver (VLTOR MUR), good stock (my preference is PRS) and a good trigger, you would be shooting right in there. I don't know how close to 1/2 moa, but it should beat my rifles. Good luck with it and post some pics, after you get something put together.

Another upper option to possibly look at is the Seekins IRMT upper, that has connection points for the handguard into a block on the front of the upper instead of the barrel nut.

I don't have one of the Seekins, but I do have a couple of their poor-boy cousins (Aero Enhanced), and the Aero version seems like a very stiff (albeit heavy) upper and handguard. I assume the Seekins version would be very nice.

I have only put together a half dozen ARs, but that small bit of experience strongly suggests to me that a quality barrel is priority one. I've used common, ordinary barrels and they've shot okay but when I used Black Hole Weaponry barrels things worked noticeably and quite obviously better. Most recently I acquired a large frame AR in .260, which I basically stripped down to upper receiver, lower receiver, barrel and bolt and rebuilt (I think "reconfigured" would be a more appropriate term) to solve functional issues and to suit my own desires. The second trip out to the range with sixteen different handloads using five different powders yielded nine out of sixteen five shot groups under one inch. That is by far the best I've ever had any rifle perform during load development. The receiver set is premium stuff, but IMO the biggest reason for that performance has to be the Lilja barrel.

If I ever build another rifle it will likely be barreled with another premium barrel.

I've never seen a negative report on Lilja barrels as far as performance goes & they were one of the original suppliers of barrels to Crane for the early Seals weapons development.

I didn't mention them because the are really on the high end, price wise, as in well over $600 & also because I don't own one nor do I directly know anyone that does.

But there's no doubt that a quality barrel is the basis & the engine of an accurate rifle, AR or bolt.

Once in awhile, you get really lucky with a cheap(er) barrel, but part of what you are paying for in a high quality barrel is consistency, barrel, to barrel, to barrel so that you know when buying one that it has a very high probability of good performance. With most cheap barrels, it barrel roulette, & like in the casino's, mostly you lose.

JMHO, YMMV

MM

Just out of curiosity, I'd shoot 2 10 shot groups side by side on one sheet of paper. Get back to us on the results.

OK, I just ordered a WOA service rifle 20" 1-8 postban, We'll see what happens.

Nice. Please keep us posted!!! I've had 1 WOA barrel and it shot lights out.