I will admit as I was reading your post, my mind was wondering how in the world did you fit a .38/55 into a .300 blk AR!

Was testing a new powder in my 38-55 Marlin Cowboy today, in between strings of fire while allowing the Marlin to cool down a little from chronographing loads, I was working on setting up the new adjustable gas block on my suppressed 300 Blackout SBR. Was so focused on what I was doing I forgot to put my ear muffs back on before grabbing the Marlin and triggering a hot load across the chronograph.

Thankfully the barrel is 24 inches long and not a shorty could have been worse, still rung my ears a little, actually was a little stunned at first until it dawned on me I forgot the muffs.

Gunner

ps
write up on the powder/loads coming