Followup to the rifle post

It has a H3 heavy buffer.
Has a standard +25% buffer spring.
The gas block is a Superlative Arms adjustable.  When you adjust it to lower pressure, it vents the excess out a port in the front of the block.  It's been adjusted to release to the limit it will go before, though next time I shoot this I'm going to take it all the way down and try it again,  Because why not?

Same with various magazines.

I've talked to two good gunsmiths, one looked the rifle over thoroughly and said he didn't know, the other, after various talks, suggested it's cursed.  Yes, I do know they're good.  This one has them baffled.

I've done more reading the past couple of months on this type rifle, and various things people have tried on theirs...

I'm going to think about all this some more before I mess with it again, and go from there.  And I do appreciate all the ideas.  And I'll try to contact that one guy mentioned.