.308 AR Accuracy Build Advise

[KillerCucco]

I am getting ready to build my first ar, and could use a little advice on what parts will ensure accuracy. First, here's my planned parts list so far:

JMT polymer AR 10 lower
Aero precision upper
15" keymod handguard
Magpul furniture
Adjustable gas block
Nickel boron BCG
20" fluted SS barrel .308 (?)
trigger (?)

My goals for this build are to keep it around $1200 (although that might be optimistic), around 9 lbs naked, and be capable of sub moa. I plan on using it for hunting as well as long range target practice. Later on I will be adding a bipod and a scope, but I'm mostly concerned with the rifle for now.

What I have been struggling with is how to choose parts that allow it to perform accurately and reliably. Will I have issues mating a JMT lower to an Aero Precision upper? Does the BCG affect reliability? How do I choose a barrel, and is 20" sufficient for 800-1000 yards? How much difference is there between a mil spec, $100 and $400 trigger? And do you recommend an adjustable gas block?

Sorry this turned into a wall of text, but I appreciate any advise on how to choose vital components and what brands to avoid.

 

[mahmoud]

Keep the upper and lower the same brand for large frame builds.

 

[KillerCucco]

I've heard about some compatibility issues with big bore ar's, but I can't find a jmt upper reciever. I want to start with an 80% lower, is there a particular brand I should go with?

 

[KZP]

I played it safe and went with same brand upper/lower and their brand lower parts kit. Was reading some people were having issues with mismatched brands and specifically the various pivot pins may not work across all receivers.

 

[BarrettBoy]

I'd be wary of building an ar-10.
They don't have the same parts interchangeability as ar-15s.

 

[KillerCucco]

I really want the big bore for versatility, I should be able to hunt most big game with it. As far as lowers go I'll see if I can check the fit at my LGS, if not I'll get a set of aero precision receivers. Any advice on barrel/bcg/trigger? I was thinking saber drop in trigger, but that's just because of price.

 

[black max]

Why in hell would you want to use a polymer lower?

 

[mahmoud]

Stay away from these new trigger makers they might be shit and you don't want to find out the hard way. Stick with a milspec with JP springs or get a low end Geissele.

I don't recommend poly lowers or any lower made by someone different than the upper. I promise you it will not fit or fit like shit. Do your self a favor and buy a matched set.

As for barrels any of the dozens of high end barrel makers mentioned on this site will shoot sub moa.

 

[Forgetful Coyote]

For yall that have em, how are the PSA10's shooting for ya?

 

[KillerCucco]

Stay away from these new trigger makers they might be shit and you don't want to find out the hard way. Stick with a milspec with JP springs or get a low end Geissele.

I don't recommend poly lowers or any lower made by someone different than the upper. I promise you it will not fit or fit like shit. Do your self a favor and buy a matched set.

As for barrels any of the dozens of high end barrel makers mentioned on this site will shoot sub moa.

Thanks for the tip on the Geissele, I think I'll go with that. As for barrel makers I don't see a sub forum for it, am I blind? Or do you just mean different threads?

 

[black max]

Here's all the info you should need.

https://www.snipershide.com/shootin...fo-picture-thread.6252642/page-2#post-6967960

 

[hypno02]

If you expect 1moa out of a reliable polymer pieced together AR10 for $1200 I'd say you're straight up delirious. I hope you prove me wrong!