Few questions about my AR308 build.

[1Luv4SF]

Hey guys. I've been out of the gun game for awhile and it's been a long time since I've built an AR308. So I have a few questions and could use some general guidance. I'd really appreciate pics of your builds as well. I'll start off with my parts list:

JD stripped receiver set
Rainier Arms match BCG (NiB)
Primary Arms 4-14x44 DMR scope
Burris PEPR scope mount
CMMG LPK w/o trigger

Parts needed-
18" or 20" Rainer Arms Barrel
Troy MRF handguard
Geissele SSA-E trigger or CMC 3.5
Gas block
STR or B5 SOPMOD stock
Pistol grip
Muzzle break


Now if I remember correctly, you can use the AR15 stocks for the 308 build, however the buffer and buffer spring need to be 308 specific. Is that correct?

I'm also unsure as to which handguard I want. It needs to be a minimum of 10-12" and I'd use a low pro gas block. So what's out there aside from the Troy MRF?

For the trigger I need a 2 stage and I'm deciding between the Geissele SSA-E and the CMC with a 3.5 pull. I'm not sure if that's 1 or 2 stage.

For the barrel I'm leaning towards the 18" but I might go with the 20". I am sure that it will be a Rainier arms barrel though. I can't decide between Match or Ultra Match. Suggestions? I think the Match is around $310 and the Ultra Match is around $430.

I'll update this thread with my progress. For now id be really appreciative to see some of your guys' pics of your 308 builds. And I'd love to hear your suggestions. Thanks! Pics to follow.

-Robert

[Glockrocks]

Add adjustable gas block to your list, it will make things easier in the long run. Make sure the trigger you use will work on a LR/DPMS 308 platform ( they use a heavier spring ).
Handguard should be for 308, stocks same as AR 15, JP silent capture spring is a good addition if your budget will allow.
Many barrels options to choose from depending on what you want to do with it.

[1Luv4SF]

[baih777]

Your CMMG parts kit has a AR15 mag catch. You will need a DPMS LR 308 mag catch and bolt for the catch.

[nate76239]

You are correct about the stock, DPMS pattern lr308 use an ar15 carbine buffer tube but 308 carbine buffer (2.5 inch)and spring. There are a couple of brands like PSA that use a longer buffer tube so that it can use an ar15 H carbine buffer (3.25 inch)

[LBDamned]

Your CMMG parts kit has a AR15 mag catch. You will need a DPMS LR 308 mag catch and bolt for the catch.

I'm pretty sure the DPMS 308 mag catch is the same as AR15... The bolt catch however, is different for the 308.

If this is incorrect - please confirm... As I'm mid build for a custom LR308 and plan to use an AR10 mag catch.

[Devilmonkey89]

I used an AR15 CMMG LPK for my LR308, parts fit fine no issues. My set came with bolt catch. No problems with AR15 mag catch.
+1 on adjustable gas block. Both mine and a buddies LR308 had ejector smears all over the back of the case.

[LBDamned]

I used an AR15 CMMG LPK for my LR308, parts fit fine no issues. My set came with bolt catch. No problems with AR15 mag catch.
+1 on adjustable gas block. Both mine and a buddies LR308 had ejector smears all over the back of the case.

Is the end of mag catch stem flush with release button? Is your rifle featureless?

[Devilmonkey89]

Is the end of mag catch stem flush with release button? Is your rifle featureless?

Running a raddlock. Will post pic.


Edit:

[LBDamned]

Thanks for the pic Devilmonkey - as I understood, it's a bit recessed... Apparently perfectly functional (as others have attested to) - but I'm pretty sure that's a standard AR15 catch (I dont think DPMS makes a different one for LR308)... The AR10 catch is supposedly a bit longer - and flush

Sweet choice for upper! I'm using Salt Works too - in an attempt at ultralight (not divulging other parts yet )

ETA: not to imply lower isn't as sweet... I'm going a different route for specific reason.... But SWR is a great choice for lower too!

[1Luv4SF]

Here's some more pics. I picked up an STR stock and BB yesterday. The LPK is 308 specific so all the parts should fit without issue. I'm going to buy the barrel online today. I've decided on the Rainier Arms 18" Match. But I'm unsure of which has system to get with it. Rifle or Carbine length?

[1Luv4SF]

My PA DMR scope has been attached to my AR15 so that it could get some use while I'm finishing the new rifle. I'm very impressed with it so far.

[Cadre]

looks good OP keep us posted.

[nate76239]

For 308 rifle length gas would be better. I have a dpms oracle that is carbine length seem like it might be over gassed. If I got an adjustable gas block I would have to remove the rail to adjust it, if it was a rifle length gas then the gas block would be sort of easier to access. Theres a few thread I'm sure you can find one a few days ago with hornady super match ammo primers getting holes punched in them where hornady only recommends rifle length gas

[1Luv4SF]

So your saying that with an 18" barrel, I can use either a carbine or rifle length gas system, but the rifle length is better in your opinion? I assumed that only one type of gas system length is correct for an 18" barrel. I'm confused now.