I emailed DPMS concerning the .308/7.62x51 LR-G2 and received this response:
Good afternoon,
You can use both 308 and 7.62x51 ammo. We only recommend using American factory loaded new brass with the G2 rifles.
From: @hotmail.com
Sent: February 27 2019 03:47:46 PM
To:info@dpmsinc.com
Subject: DMPS Model LR-G2
Hello,
I purchased a used DPMS Model LR-G2.
All I am reading on the internet leaves one a little confused.
This weapon is stamped on the barrel 7.62x51 1-10 G2.
On the receiver is stamped Model LR-G2 Caliber Multi