SCARCQB
Get Opp my rawn, Plick!
I had a similar event with a home assembled AR 9 pistol.
I made the error of using a standard Weight AR buffer. Since these are direct blowback weapons. I may have had timing issues and an out of battery discharge. I switched to a stainless steel 10 oz pistol buffer( longer and heavier) It’s been reliable since.
When I had the standard buffer in. ( 3.6 oz) the fired cases were extremely bulged at the base.
I made the error of using a standard Weight AR buffer. Since these are direct blowback weapons. I may have had timing issues and an out of battery discharge. I switched to a stainless steel 10 oz pistol buffer( longer and heavier) It’s been reliable since.
When I had the standard buffer in. ( 3.6 oz) the fired cases were extremely bulged at the base.