I have an lr308 that would jam more than 50% of the time.  See the video.


I had issues with an LR308 failing to feed more than 50% of the time.  The issue I found was the feed lips on the magazine (Gen 3 PMag) were long enough to cause issues.  As the bolt rode forward, it would push the round to the m4 feed ramp, then as the round hit the ramp, it would pivot around the front of the magazine lip- the front of the round rode up in to the chamber, and the rear of the round went down below the bolt, causing the bolt to ride over the rim of the round, and jam as seen.  The solution was to grind away the front of the magazine lip.  I took the magazine to a bench top grinder, and made no measurements nor did anything with precision.  You may need to find what works best for you.


https://youtu.be/zmvGjUL_mDw

I wanted to post here because I read a lot for over a month, never saw anybody suggest this as a solution.

Fixed.  Sorry it’s have been over a year since I posted on ARF