"Once fired" Brass I bought already Sized (from 2 dif people) fits Perfect
If I load one and Shoot it, there is No gap, it Ejects fine, but if I pick it up and put it back in, it will not close without a gap ... I draw on it with a Sharpie, run through my die it re sizes, with uniform contact, but still will not fit.
If i mark the shoulder with a shaprie on one that will not fit, put it in and close the chamber 1/2 doz times, they marks are not disturbed, it's like the Head it's self has grown.