MEC 600 Jr. 12 Gauge Mark V Single Stage Press With 1-1/8oz Charge Bar and #29, #30, #32 Bushings The MEC 600 Jr. Mark V is the most popular shotshell reloader. Adjustable for 3" shells. Order extra bushings and bars separately. Novice and seasoned gunners will appreciate these new features along with the time-tested excellence this single-stage reloader has provided over the years with quick, simple operation and a minimum of effort. The MEC 600 Jr. Mark 5 can load four to six boxes per hour. Best of all, the price won't shoot anyone's budget.