I have three MEC 600 Jr's for sale. The 12 gauge has the automatic primer feeder, the 16 gauge has an adjustable powder-and-shot bar and the 20 gauge is just a 20 gauge. I have used the 12 gauge, though not the primer feeder,and the 16 gauge, but not the 20. All appear to be in good functional condition. With some practice and a little luck I have loaded 10 boxes, yes 250 rounds, in an hour on the 12 gauge machine. $65 each, a fraction of new retail cost. I do have a small selection of shot bars and powder bushings if you know what you want I will trade out if I have it. Always consider offers and trades. 12 GAUGE SOLD!! THANK YOU!! 16 GAUGE SPF!! THANK YOU!! 20 GAUGE SOLD!! THANK YOU!!