300 Blackout problems hopefully solved

[john hayslip]

I have a 300 Blackout on a DPMS lower. Before last Christmas I bought some Remington sub and supersonic ammunition which worked fine. My first reloads seemed to be ok and then the rifle began to snap, no primer indication, and I'd have to use tools to get it open.

Couldn't figure out what was wrong. Brass was trimmed to max and would chamber without a bullet but as soon as the bullet was inserted things went south quickly. I couldn't find anything wrong.

The other day I decided to shorten the cases a little under max and try that and a dummy seemed to work so I loaded a few up and intended to go to the range Monday but when I got there it was closed so the roads could be sealed. Just returning from there with a smile on my face. Only fired three rounds. First I loaded one singly and it shot and held the bolt open. Then loaded 2 and fired them and it left the bolt back. Load was 8.4 grains of H110 under a Sierra 110 grain hollow point. two of the brass were in about 6 inches of each other about where the rifle throws 223 cases and the other one hit something and riccocheted a little further away.

Now I can quit pulling the hair out of my head.

[xacex]

I have a 300 Blackout on a DPMS lower. Before last Christmas I bought some Remington sub and supersonic ammunition which worked fine. My first reloads seemed to be ok and then the rifle began to snap, no primer indication, and I'd have to use tools to get it open.

Couldn't figure out what was wrong. Brass was trimmed to max and would chamber without a bullet but as soon as the bullet was inserted things went south quickly. I couldn't find anything wrong.

The other day I decided to shorten the cases a little under max and try that and a dummy seemed to work so I loaded a few up and intended to go to the range Monday but when I got there it was closed so the roads could be sealed. Just returning from there with a smile on my face. Only fired three rounds. First I loaded one singly and it shot and held the bolt open. Then loaded 2 and fired them and it left the bolt back. Load was 8.4 grains of H110 under a Sierra 110 grain hollow point. two of the brass were in about 6 inches of each other about where the rifle throws 223 cases and the other one hit something and riccocheted a little further away.

Now I can quit pulling the hair out of my head.

Stuck case? You don't need to use tools to get it out. In fact you can damage your upper. Use inertia by pulling on the charge handle while striking the butt on the ground.

I would check the length of the cases of factory ammunition, and trim to that length. The Wilson case gauge is a life saver with the 300 blackout.