The plastic plug came out of the buffer today. Thread failure. IIRC 3 weights & thin shim. Haven't weighed it yet, should be carbine. First one I've seen NOT pinned in. Seems lie it rattles a lot more than I'm used to but don't really pay much attention to the buffer. I get another one, just wondering if this thing is really a kluge (given to me) or bad design. Thoughts?