20" 6ARC Gas Block Question

[Thelaststraw]

I use the Hornady comparators and they work good,  I just got confused on the fireformed dimensions, converted dimensions and unfired Hornady brass dimensions.....most importantly I didn't bump the shoulder back enough and was 0.003"+ longer than fireformed factory brass on my converted handloads (lesson learned). I got the rifle and dies dialed in now. Much more fun and engaging than mass loading 9mm.