Image 1 of 1 SM-1 BARREL INSERT KIT SEMI-GLOSS BLACK $65.00 sold out SM-1 barrel insert kit semi-gloss black compatible with SM-1 Tactical and Orbium barrel backs3 inserts .683 .684 .685 Sold Out Added! SM-1 barrel insert kit semi-gloss black compatible with SM-1 Tactical and Orbium barrel backs3 inserts .683 .684 .685