20" A2 build going featureless... receiver extension (tube) and buffer required?

[the86d]

Alright, it cycles fine with industry standard parts with a carbine length receiver extension and buffer w/a 20" barrel.

The only issue was the same as before, with (underpowered?) steel cases and short stroking is the same with a full rifle-length receiver extension, or carbine-length.

Brass cases, with regular loads worked fine.