Thread: Trouble getting 300 Blackout to shoot and cycle subs

Probably not what you want to hear but it could be a number of things.
I note you have brass rash behind the ejection port which could indicate ejector spring strength, extractor issues and or load issues.
I personally would start by changing powders.

Fault finding can be a huge process with a really simple soloution. Frustrating.
Plenty of people on here with experience in the subsonic department will chime in with better advice I am sure.

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