i just built a 9mm PCC. Pro2a Upper, with Gibbz NRSCU, 16" faxon barrel. Nordic Components M&P lower, Chip McCormick 3-3.5 lb trigger - after reading several posts, articles, etc, I ended up getting the 7.5 oz KVP buffer, w/KVP Mil-spec tube (came together).
The problem that I am experiencing is that about 25% of the time, the action isn't fully cycling. Using average, inexpensive 115Gr FMJ.
It ejects and loads another round, but doesn't fully cock the hammer - Could this be caused by a too heavy buffer spring or buffer? Does anyone have a suggestion for make/model of a more appropriate buffer spring/buffer combination?