Mossberg 20 gauge stock adapter. 12/20 Gauge. FLEX Conversion Kit: Stock & Forearm Adapter, 20 Gauge . (Travis Pike Photo) Introducing the Nova Tactical 12-Gauge Shotgun: Your Ultimate Companion When it comes to reliability and versatility, the Nova Tactical 12-gauge shotgun stands tall as the epitome of dependability. Products 30 items NDZ Mossberg 500 535 835 590 930 Magazine Follower 12 & 20 Gauge Aluminum USD 14. 00 #14817 Shotgun Forearm, Synthetic, 20 Gauge Out of stock $34. Mossberg 500 590 Shockwave Maverick 88 12 & 20GA Shotgun Stock Grip With Pad USD 66. 00 #14472WS Shotgun Forearm, Wood, 20 Gauge. Shotforce Top-Folding Shotgun Stock Rated 4. Detent Ball. 410-Gauge AR Stock Adapter $37. ldx yijrb nybfcio fpphx yecr ymw qmw rlzcba vvroivw wvt