First off, I love shooting my ole Mosin. It's a fun gun to shoot with reduced loads.
I have noticed over the past few outings with my Mosin that out of 25 loads, 5 or 6 will be hard to chamber and 1 or 2 won't chamber !!!.
All bullets resized and reloaded with same dies using the same bullet at the same time. The chamber is clean when I start shooting. I shoot the Lee C312-185-1R with GC over 8.2 / BE sized to .311. In my rifle it's a nose riding bullet.. The bullet gets a light coating of LLA.
What's causing this ???