Lots of soot on spent cases

[bultinkle]

Heavier buffer

 

[FireFlyFishing]

When I do size my brass, I'll run them through a wet tumbler for a bit to get them clean. With my AR brass, I clean them before and after sizing.
I've got a Superlative Arms adjustable block but installed the normal gas block first just to see if I could use it and save the adjustable for a different build, but I'm definitely not opposed to swapping it out.

I run adjustable gas blocks on all my auto loaders. It allows flexibility for any changes you enter into the system…like a suppressor or a change in ammo. It allows you to dial the rifle into proper/optimal operation.

I clean all my auto loaders' brass well. 1. I don't want malfunctions. 2. I do high volume loading on these cartridges, so I want longevity on my dies.

 

[Zen Archery]

Just realized I left out the part about the brass. My reloads you see there are virgin Starline brass—expanded, chamfered, and primer pockets uniformed. I do anneal but not on this first firing.

My experience with virgin starline cases grow 1.0-2.5gr H20. The bigger the case the more expansion. Not saying that's the issue. But I've never considered dirty cases a problem if it's accurate and running.