I've seen the threads on an adjustable MEC bar. I always used bushings and was more concerned with grains of powder. I just got a new electronic scale and my 1 1/8th shot bar is only 1.05 oz. of shot. Weighed each shell in my last 25 ..and had to add approx. 30 -7 1/2's to reach 1 1/8th ( 1.125) Oz. Kind of concerns me with PSI/FPS/etc. Weighed my 1 1/4 bar and it was 1.19 oz. ..probably off by another 30-35 pellets. Anyone ever REEM out a MEC bar to be EXACT? MEC bushing are usually conservative......but I never thought about SHOT.