.308 AR FAQ Page

Then was originally posted on ARFCOM but I thought it would be good here also

Wikipedia Entry on 7.62x51 / 7.62 NATO

Q: Don't all 'AR-10s' / .308 ARs use the same parts?
A: NO! There are several different upper receiver styles, 3 different magazine formats used, and RRA even uses a different thread for their upper receivers (so you can't use standard barrel nuts or free float systems). For more infomation see:
The AR15.com Armalite AR-10 FAQ as well as continue reading below.

Q: What parts are different from company to company?
A: Upper Receivers, Barrel nuts (Armalite, DPMS, and RRA use different thread pitches), magazines may be different, gas tubes can be different (Armalite's are longer than DPMS's).

Q: What parts from an AR-15 can I use in a .308 rifle?
A: (from the AR-10 FAQ)
# Pistol grip

# Ejector/Safety spring

# Safety detent

# Buttstock screw (A2)

# Buttstock Assembly (A2)

# Buttstock Assembly (A2)

# Buttstock spacer

# Detent spring

# Detent (2 per rifle)

# Bolt stop pin

# Bolt stop plunger

# Bolt stop spring

# Mag catch button

# Mag catch spring

# Safety selector

# Rifle receiver extension

# Disconnector

# Disconnector spring

# Standard Trigger

# Trigger spring

# Hammer

# Hammer spring

# Hammer and trigger pin

# Trigger guard pin

# Trigger guard assembly (on some rifles - others have built in trigger guards)

# Buffer detent

# Buffer detent spring

The AR-15 Bolt catch should work on KAC/DPMS type lowers, but not AR-10 type lowers.

From DnPRK: Most AR trigger assebblies will fit an LR-308. The two triggers that require modification are 1) the Chip McCormick straight trigger which needs th end of the trigger clipped to clear the trigger guard and 2) the RRA trigger which might require the tip of the cocked hammer to be clipped to prevent it from dragging on the bottom of the bolt carrier.

An AR-15 rifle buffer tube will fit an LR-308, but you need the 308 rifle buffer and spring.

A CAR-15/M-4 collapsible stock buffer tube will fit an LR-308 but you need to use a Slash shortened buffer and 308 spring, or use Armalite's collapsible stock buffer, tube and spring for the AR-10 carbine.

Q: Are the AR10 and LR-308 Lower parts kits interchangable?
A: (from shrikefan) YES, however, the fit will not be ideal and the pins may require some polishing down to size with emory cloth. The pivot pin and the takedown pin will be too short or too long depending on which kit is used with which lower. Not the IDEAL set-up but it will work in a pinch. The bolt stop may or may not work but it is not critical for the BANG function of the gun.

Rifle Manufacturers
# Armalite (1950s)

# Armalite (modern) (A2 or Flattop Uppers, 16", 20", 24"

# Eagle Arms
('Armalite AR-10' type rifle)
# Noveske
('Armalite AR-10' type rifle)
# LaRue
(DPMS Magazines; 16.1'; Monolithic upper with 20moa cant )
# DPMS (DPMS Type; 16", 18" , 24")

# Fulton-Armory (DPMS Type; 16", 18.5", 20", 22")

# Patriot Arms (DPMS Type; 20")

# Remington (DMPS Type; 20" {made by DPMS})

# Bushmaster (used FAL magazines, no longer produced - but some info on their short lived offering)

# RRA (Bushmaster Type; A2 or Flattop upprs, 16", 20", 26", uses a unique upper & barrel nut)

# Knights Armament (Stoner Type; 16", 20")

# POF
(Piston operated; 14.5", 16", 20")
# LWRC (Piston operated; Side or Rear Charging; 12.5", 16.1", 20")

# Armerican Spirit Arms (side charging)

# JP Rifles

Custom Rifle Builders
# Georgia Precision ('Armalite AR-10' rifle)

# Accuracy Systems (Armalite & DPMS rifles)

# Hofmeisters Custom Shop (Armalite & DPMS rifles)

# Gun Creations (DPMS)

# X-Ring Precison Rifle (Armalite & DPMS)

Sources for Complete Uppers
What lowers do these work on?
# Noveske (Armalite Type; 12.5", 14.5", 16", 18", 21")

# Armalite (Armalite Type; 16", 20", 24")

# DPMS (DPMS Type; )

# Fulton-Armory (DPMS Type; 16", 18.5", 20", 22")

# POF
(DPMS Type; Piston operated; 14.5", 16", 20")
# AR15Barrels.com

# Accuracy Systems (Custom Armalite & DPMS Types)

Sources for Stripped Lowers
# CMMG (Armalite Type, DPMS Type, DPMS/G3 Type (takes DPMS uppers, G3 Magazines)

# Aero Precision (Armalite Type)

# Noveske (Armalite Type)

# Eagle Arms (Armalite Type)

# DPMS (DPMS Type; optionally marked for .243, .260, .308, .338, 6.5 Creedmore)

# Fulton Armory (DPMS Type)

# CWS ( POF - uses DPMS magazines, and with a sleeve can use DPMS uppers)

# Rainer Arms ( POF - uses DPMS magazines, and with a sleeve can use DPMS uppers)

# DDs Ranch ( POF - uses DPMS magazines, and with a sleeve can use DPMS uppers)

Sources for Stripped Uppers
# DPMS

# Fulton-Armory (DPMS Type Flattop; with and without foward assist, sidecocking option)

# Armalite (A2 and flattop style available)

Sources for Bolts
# DPMS

# Fulton-Armory

# Armalite

Barrel Manufacturers
# Armalite

# DPMS

# Noveske

# Krieger

# Fulton-Armory

# AR15Barrels.com

Whose Uppers fit whose Lowers?
A: Armalite uppers WILL fit on DPMS lowers, but you have a gap in the back where the Armalite upper has the 45 degree angle cut. DPMS uppers WILL NOT fit on a Armalite lower.

Stock Options?

FF Tube/Rail Options
# LaRue (Armalite upper)

# Badger Ordnance (Armalite upper)

# PRI (Armalite upper)

# DPMS

# Daniel Defense

# SWS

# JP Rifles

Other Specialty Parts
# PRI - Gas Buster charging handle

# Clint (Slash /

HeavyBuffers@gmail.com

) - custom buffers to allow use of AR-15 receiver extensions.

# LaRue - AR-10 gas blocks

Magazines
There are primarily two magazines styles for the .308 rifles, the original Armalite-Fairchild magazines used in the original AR-10s, then picked up by the KAC SR-25 (henceforth called the SR-25 Type) and the Modern Armalite AR-10 type which is a modified M-14 magazine. It should be pointed out RRA (and formerly Bushmaster) make rifles that use FAL magazines, and CMMG has a lower which uses G3 magazines.
# Armalite AR-10 type (used by Armalite, Noveske, Eagle Arms, Georgia Precision; capacities: 5, 10, 20, 25)

# SR-25 Type
(used by DPMS, KAC, LaRue, POF, LWRC, JP Rifles, 1950s Armalites, Remington, Fulton-Armory; capacities: 4, 10, 19, 20)
# FAL Magzines (Metric or Inch pattern; used by Bushmaster, RRA; capacities: 5, 10, 20, 30)

# G3 Magazines (CMMG .308 Lower)

Magazine Manufacturers
# C-Products (SR-25 type; 19 rounds)

# Armalite (Armalite Type; 5, 10, 20, 25 rounds)

# POF ( SR-25 Type; 25 round

Alternate Calibers for use with the .308/7.62x51 Lowers?
# .243 Winchester

# .22-250

# .257 Roberst

# .260 Remington

# 6.5 Creedmore

# .270 WSM

# 7mm WSM

# 7-08 Remington

# 284 Winchester

# .300 WSM

# .300 RSAUM

# .300 Savage

# .338-7mm Benchrest

# .338 Whisper

# .338 Federal

# .35 Remington

# .358 Winchester

# .450 Marlin

# .500 Phantom (currently not in production)