What makes an accurate AR?

[ricklovin93]

New AR build in progress.
Ive done cheap budget builds (Basic M4 style carbines) that shoot roughly 2-3 moa with Irons and with standard XM855.

This one is going to be different. The goal is sub MOA. obviously with optics.
My plan is an 18" SPR profile barrel. How important is the BCG to accuracy? What else should I not cheap out on?

 

[Darth]

The shooter.

 

[meketrefe]

Because this has been covered so many times I am going to be brief and cut to the chase.
The beating heart of the AR is the bolt and carrier group. gas block and such is part of the DI too.
The carrier is not as important as the bolt itself and a good extractor and if possible get a quality barrel
made headspaced to that bolt and ammo in question. I would go for one of the match reamer variants that
will allow you to shoot any ammo but specially the best ammo the AR has to offer.
The rest is just the shell but have a reciever that is tight and lap it, obviously adding a floating handguard
ideally something not too heavy or bulky but well suited for some support where as they are bags, barricades
or bipod. Stay away from long rails and round guards although you can slot them with some ladders.
Then it comes the trigger. Geisselle is a very good choice but a 2 stage RRA will be budget and by conditioning
the springs and trigger will do the same. leave it at no less that 2-3lbs.
Get a steel gas block of the clamp type. Something small and very light ideally stainless steel. Make sure the barrel
is rifle ported and properly sized on the port. The gas tube has to provide a perfect seal. a drop of thread locker
will help.
Spend on the barrel, bolt and trigger and the rest keep it light and keep it simple.
Brands do not mean much if they are cut up to spec and they fit well. A shell is a shell.
Like a UTG pro handgard will do the same or better than tacticool guards costing 4 times more.
plan on a quality glass and mount with a cantilever that is not too long so you have more support on the glass.
Also bridge the upper with the rail if you wan using a 2inch extension but w/o touching the mount or rings
of the glass.
This will give greater rigidity to the gun w/o adding weight and in the area where the AR is weaker when put under
load that is the cut between the receiver threads and the receiver itself. That is why no matter how much one
spends it doesn't matter becuase all receiveers are the same at this critical area and the custom systems
are just not worthy for something one can achieve with a 10 dollar part.

Don't get sidetracked by brands and BS and stick to the basics and you will be ok.

If you want I can tell you makers and parts I had good experiences with and why but there are so many to choose from.

Some OEM mills make for several brands so that is why brands do not mean much. But I would say if you can stick to
some of the ones that have the machines and good track record that mitigates some of the variables one might find.

Also plan to get some training for shooting. Some folks learn more in one day with a pro than in their entire life of self study.

Use the search too.

 

[BDinPutnam]

^^^Stickey that, please.

 

[masterswimmer]

Because this has been covered so many times I am going to be brief and cut to the chase.
The beating heart of the AR is the bolt and carrier group. gas block and such is part of the DI too.
The carrier is not as important as the bolt itself and a good extractor and if possible get a quality barrel
made headspaced to that bolt and ammo in question. I would go for one of the match reamer variants that
will allow you to shoot any ammo but specially the best ammo the AR has to offer.
The rest is just the shell but have a reciever that is tight and lap it, obviously adding a floating handguard
ideally something not too heavy or bulky but well suited for some support where as they are bags, barricades
or bipod. Stay away from long rails and round guards although you can slot them with some ladders.
Then it comes the trigger. Geisselle is a very good choice but a 2 stage RRA will be budget and by conditioning
the springs and trigger will do the same. leave it at no less that 2-3lbs.
Get a steel gas block of the clamp type. Something small and very light ideally stainless steel. Make sure the barrel
is rifle ported and properly sized on the port. The gas tube has to provide a perfect seal. a drop of thread locker
will help.
Spend on the barrel, bolt and trigger and the rest keep it light and keep it simple.
Brands do not mean much if they are cut up to spec and they fit well. A shell is a shell.
Like a UTG pro handgard will do the same or better than tacticool guards costing 4 times more.
plan on a quality glass and mount with a cantilever that is not too long so you have more support on the glass.
Also bridge the upper with the rail if you wan using a 2inch extension but w/o touching the mount or rings
of the glass.
This will give greater rigidity to the gun w/o adding weight and in the area where the AR is weaker when put under
load that is the cut between the receiver threads and the receiver itself. That is why no matter how much one
spends it doesn't matter becuase all receiveers are the same at this critical area and the custom systems
are just not worthy for something one can achieve with a 10 dollar part.

Don't get sidetracked by brands and BS and stick to the basics and you will be ok.

If you want I can tell you makers and parts I had good experiences with and why but there are so many to choose from.

Some OEM mills make for several brands so that is why brands do not mean much. But I would say if you can stick to
some of the ones that have the machines and good track record that mitigates some of the variables one might find.

Also plan to get some training for shooting. Some folks learn more in one day with a pro than in their entire life of self study.

Use the search too.

Whoa!

 

[cgrutt]

I am going to be brief and cut to the chase.

Lol...

 

[Acer-m14]

I could say something but i wont .. would involve a hot chick with fangs

 

[Mosinitis]

No mention of quality ammo? Surely it is more important than bolt and extractor, which only have to be within specs.
Buy from White Oak Armaments. You will pay for quality only for the parts that need it. Barrel, trigger and freefloated handguard have to be of good quality and worth paying more. The rest of the parts have to be just within specs for good function and assembled correctly for accuracy.

 

[Mosinitis]

AR accuracy is a function of good equipment, good ammo and last but not least shooters skill. All three have to be there.

 

[meketrefe]

Another thing get a M16 type or match carrier vs. the slanted semi-auto. The extra mass is a good thing.
Of all the carriers and bolts I have the young manufacturing are among the best.

Bolts are great, like ARP they are made of 9310 Vac Arc that is the purest and strongest alloy for this duty vs. the typical carpenter steel.
Also the radius around the lugs can cam have been increased so there are about 15-17% stronger than the average bolts.
This is even more critical with the 6.8 and specially the 7.62x39/grendel bolts that about the only ones that do not break
with time.

The advantage of working with a company that makes the barrels and provides specific type of carriers and bolts is that
they make sure tolerances are the best possible while assuring proper function.

Armalite makes very good extractors properly heat treated and weather they are for 5.56 or the x39 or Grendel that is more
critical due to the steel cased hp ammo.

All this MP and HP testing is a marketing bait. They do not do it. Only FN and Colt do proper HP testing ( along with HK) for their service
bound rifles. Everything else is a lie because there is no standard. Good companies are in fact above mil spec like the ARP bolts
that work with regular extensions.

Stay away from "super deal" kits like those from model1, PSA, cheaperthanchit, etc....

Just to give you a few examples when things went wrong and parts broke.

-Remember a few years back when the midway brand called Stoner had to recall thousands of bolts because they were breaking
left and right? Well it was a heat treatment problem and because they are Midway they quickly recalled them and gave people
a proper one or refund. you see, many retailers put their brands in stuff then do not make and they trust their suppliers but
sometimes these fail to Test their batches and as a result all this BS shows up. Look it up in the search and other forums and
you can see how the bolts break in multiple places. RRA had simllar issues but was with a much smaller batch.

-Another example was the PSA barrel my buddy David from the other ny forum showed me to diagnose. The headspace was perfect
there was no run-out yet the brass was budged to the point it almost failed. I told him to stop shooting ASAP and brought the
barrel over. It turns out the tenon was cut short so there was no support for the web of the brass so the barrel was trash and
it could not be used. Not a very frequent event (only twice in my life) but I would not be surprised if I see it again.
In summary a machinist with ADD or scratching his berries when running the machines.

-Another fiasco was with the Black Hole Weaponry. I was the recipient of one of the many lemons they produce.
A barrel I got from them custom cut in 6x45 after a 4 month delay on the delivery date was failing to stabilize bullets.
I created a thread on this and explained to them. They were good people on the phone but never followed through. Busy I guess.
Eventually I put the barrel in my lathe and found out the bore had quite a run out about 0.095" so the job was shit and another
400 dollar barrel that went into the trash. Again a machinist failing to dial the work from the center of the bore.

So many other cases the we could write a book about mistakes only.

So bottom line, most people do not have tools and or know how to measure things but starting with some decent barrel makers
and equipment will help. If you can have the barrel headpaced for your bolt and make sure both are quality and properly dialed
and chambered.

I had very good luck with Krieger, Lothar Walter, Shilen, Bergara and Rock river barrels whether they did them themselves or
I did it in my shop. But I also had good luck with budget build from Midway (Stoner barrels are Douglas anyway) Green Mountain
(Chambering myself) and some other makers.

I was impressed by the Lothar Walter custom shop and they send you the barrels with the matching bolt that they can sell it
to you or you send them both. Depending on the caliber I might keep two bolts from the same batch to go with the one barrel.

White Oak and Fulton also sent me very good barrel and other parts.

2 barrels from Pac-Nor with polygonal rifling were excellent and these are some of the same stock and people who made the
noveske polygonal barrels.

Lesbaer produces ARs and uppers that are 1/2 moa out of the box. Whitley too. both a tad more expensive but all quality.

We are blessed with many quality options.

Also like mosinitis well stated the ammo is a huge part of the deal. The most consistent ammunition I have ever used is
lapua match (No surprise there) and then black hills. I have been using the black hills 77gr TMK and it has been nothing
but consistency and quality. That is why it is a favorite with snipers and special forces like other loads and calibers on this brand.

I would say of the main stream brands the Federal gold has been great but in my case for the 308 and for the 5.56 either
black hills or, obviouly my own reload for any of the calibers.

 

[kev74]

I bet those 2-3 MOA iron sight carbines go to 1 MOA or better with a decent scope and good ammo.

 

[Cooolone]

The shooter.

^^^THIS^^^

Can buy a Maserati, doesn't mean you can drive it!!! Lol

 

[meketrefe]

^^^THIS^^^

Can buy a Maserati, doesn't mean you can drive it!!! Lol

Good point. Specially someone with a masserati you can tell they probably dont know much about cars and driving.
One can spend a lot buying useless overrated brand equipment vs something good.