COLT SMG UPPER NO FURTHER A MYSTERY

A PCC is often helpful for defending your property, one thing exciting to shoot down for the array, and a superb varmint looking Resolution. Also, a fast rising aggressive capturing scene has arrive about for these firearms. I haven't decided on a flat best or A1 (with out FA and deflector).  I am wondering a 16" flattop, and a 10.5" with carry d