AR 308 Build Thoughts/Critique

[Vegas]

Hey all,

Looking to get some input on a building out an AR in 308. Use's are general purpose range toy and longer range steel puncher, suppressed and unsuppressed. Weight is a consideration as always but not overly important. Here's what I am considering basing the build on:

• Aero Precision M5 Receiver Set
• Rainier Arms Match Barrel 18"
• DPMS BCG (or Carrier with JP Bolt?)
• Vltor RE10 Receiver Extension
• Vltor IMOD Stock
• Geissele G2S Trigger

Undecided on lower parts kit, buffer and spring, handguard and anything else I missed. Feel free to pick it apart and provide alternatives. I am still doing my reading on 308 AR's so forgive me if any of the above doesn't work together.

Cheers.

[Tx_Aggie]

Just a heads up, the Aero lower uses proprietary pivot and take-down pins (standard DPMS 308 pins are too short) and a proprietary threaded bolt catch pin. It's also better to use Aero's 308 mag catch as a standard AR10 mag catch is a little short.

The standard Aero uppers are set up to mate with "hi-profile" DPMS style handguards so you should have lots of options to choose from. If you haven't already purchased your upper you might give the Aero Enhanced Upper/Handguard combo a look. They are pretty solid and one of the things Aero really got right (IMO).

If you like JP parts, you might also take a look at their AR10 Silent Captured Buffer.

[SomeOtherGuy]

Hey all,

Looking to get some input on a building out an AR in 308. Use's are general purpose range toy and longer range steel puncher. Weight is a consideration as always but not overly important.

For those "non-serious" uses I would consider buying a factory .308 AR. I would look at the DPMS GII, the DPMS gen1 free float options, any Armalite, and the S&W ban state M&P10 which has a heavier profile barrel without the ridiculous 4" long flash hider. The build outlined below is likely to cost significantly more than those factory rifles without delivering much clear benefit. DIY parts for the .308 tend to be much more expensive than for the AR15, with many actual or possible incompatibility issues and fewer quality options. There are also frequent threads about people who can't get their .308 build to work, and they often don't resolve as quickly or easily as a non-working AR15 build.

Here's what I am considering basing the build on:

• Aero Precision M5 Receiver Set
• Rainier Arms Match Barrel 18"
• DPMS BCG (or Carrier with JP Bolt?)
• Vltor RE10 Receiver Extension
• Vltor IMOD Stock
• Geissele G2S Trigger

Undecided on lower parts kit, buffer and spring, handguard and anything else I missed. Feel free to pick it apart and provide alternatives. I am still doing my reading on 308 AR's so forgive me if any of the above doesn't work together.

Cheers.

You can get a Toolcraft BCG from WCArmory for around $140 and I would take it over a DPMS any day of the week. Other options that I would prefer over DPMS are ADK Arms and AIM Surplus.

I would consider barrels made by Faxon Firearms and Ballistic Advantage / Aero Precision, in addition to the one you listed.

[veeref]

Hey all,

Looking to get some input on a building out an AR in 308. Use's are general purpose range toy and longer range steel puncher. Weight is a consideration as always but not overly important. Here's what I am considering basing the build on:

• Aero Precision M5 Receiver Set
• Rainier Arms Match Barrel 18"
• DPMS BCG (or Carrier with JP Bolt?)
• Vltor RE10 Receiver Extension
• Vltor IMOD Stock
• Geissele G2S Trigger

Undecided on lower parts kit, buffer and spring, handguard and anything else I missed. Feel free to pick it apart and provide alternatives. I am still doing my reading on 308 AR's so forgive me if any of the above doesn't work together.

Cheers.

I would take a look at a Mega Maten set. I built mine with a 16" Mega barrel and DPMS bolt. I strongly recommend an adjustable gas block. I use a Superlative Arms. I switched to an A5 RE with an XH heavy buffer. It eats all types of ammo suppressed and unsuppressed.

I like the Mega set because it includes a lot of the lower parts already built in. All you need is an AR-15 LPK.

Like others mentioned, they can be more finicky with parts but I've found running a heavier buffer and using a standard DPMS bolt solves most issues.

[Vegas]

Just a heads up, the Aero lower uses proprietary pivot and take-down pins (standard DPMS 308 pins are too short) and a proprietary threaded bolt catch pin. It's also better to use Aero's 308 mag catch as a standard AR10 mag catch is a little short.

The proprietary parts bother me but at least they sell them separately on their site so I don't have to use their entire LPK. My understanding is the Battle Arms extended mag release solves the issue with the mag catch.

For those "non-serious" uses I would consider buying a factory .308 AR. I would look at the DPMS GII, the DPMS gen1 free float options, any Armalite, and the S&W ban state M&P10 which has a heavier profile barrel without the ridiculous 4" long flash hider. The build outlined below is likely to cost significantly more than those factory rifles without delivering much clear benefit. DIY parts for the .308 tend to be much more expensive than for the AR15, with many actual or possible incompatibility issues and fewer quality options. There are also frequent threads about people who can't get their .308 build to work, and they often don't resolve as quickly or easily as a non-working AR15 build.

You can get a Toolcraft BCG from WCArmory for around $140 and I would take it over a DPMS any day of the week. Other options that I would prefer over DPMS are ADK Arms and AIM Surplus.

I would consider barrels made by Faxon Firearms and Ballistic Advantage / Aero Precision, in addition to the one you listed.

There's a good chance I would end up switching out parts from a factory gun so I not sure the savings would be realized but worth looking at either way. I need to price the build out once I have a better idea of the parts I would be using. I'll definitely take a look at the Toolcraft BCG.

I would take a look at a Mega Maten set. I built mine with a 16" Mega barrel and DPMS bolt. I strongly recommend an adjustable gas block. I use a Superlative Arms. I switched to an A5 RE with an XH heavy buffer. It eats all types of ammo suppressed and unsuppressed.

I like the Mega set because it includes a lot of the lower parts already built in. All you need is an AR-15 LPK.

Like others mentioned, they can be more finicky with parts but I've found running a heavier buffer and using a standard DPMS bolt solves most issues.

Thanks for the insight on your build, it reminded me to edit my OP as I'll running suppressed also. I like my Mega AR15 lower so that is an option too but obviously pricepoint is higher than the Aero receiver set.

[Vegas]

Did a quick rundown with a bit more detail on parts. Switched out to the Saltworks Builder set for lower/upper/handguard, roughly the same price as the AP stuff. Add a couple of hundred more for the Mega set with their handguard if I switched out for theirs. Also add another $150 if I went with the Rainier Match BCG. That one is a serious consideration for matching up with the barrel. Not sure about the buffer. Veeref above has good experience of it but $125 for a buffer makes my eyes bleed, lol. Perhaps if I pick up a deal on the trigger when they go on sale it will offset it a bit. No stock listed as I already have the Imod in the spare parts bin. Also have a Specwar 7.62 brake on hand too. So question is, how does this build look compared to what is on the market for prebuilt rifles in the $1500 - $2000 range?

[veeref]

What length gas is your Rainier barrel? I am running a Mega 16" mid-length on mine.

The only reason I mention Clint's XH buffer is you mentioned you're running a suppressed setup. My setup was extremely over-gassed before I added my can and even with my gas adjustment screw all the way out it was cycling pretty hard and causing feeding/extraction issues with a standard AR-10 buffer.

You could run your setup as you listed but you may/may not have reliability issues. The other thing I ended up swapping out was the bolt for a JP high-pressure because I was getting cratered primers. Either way I would avoid NiB coated bolts. I learned this the hard way when my barrel/bolt wouldn't headspace properly. That NiB coating wouldn't let my bolt close properly.

[SomeOtherGuy]

So question is, how does this build look compared to what is on the market for prebuilt rifles in the $1500 - $2000 range?

For $1636 +/- you could instead get:
-almost any DPMS (yeah, OK)
-any S&W M&P10 version (ditto)
-Ruger SR-762
-most Armalite models
-a Colt M.A.R.C. 901 with the non-monolithic upper, but a free float handguard, if you can find one

For any of those the factory trigger isn't equal to a G2S and you might want to spend that extra $150 on a G2S. You would still be at or below $1636 with a G2S trigger.

For a few more coins you could get a Colt LE901 with the monolithic upper and integrated BUIS.

The individual parts you've selected look good, individually, but you are making a one-off parts gun that will have limited resale and might require debugging to get it running. I guess it all depends on how much you like the chosen parts vs. just buying something that runs out of the box.

[FaxonNathan]

A pleasure to be mentioned. Let us know if we can help further!

[elephantrider]

I haven't seen one of the Toolcraft BCGs in person, but the AERO that I have is quite nice. It appears to have a High Pressure style firing pin with corresponding smaller firing pin hole i the bolt face. The AERO may well be the same as the Toolcraft. The AERO uppers and lowers that I have checked out have all been nice. I' have a Faxon 18" rifle gas barrel that I have not had a chance to shoot yet. I am hoping to pair it up with a KAC rifle buffer and spring. Hopefully it'll make for a smooth shooting .308. I am holding out for the Forward Controls Designs 308 bolt catch/release.