I am loading 6.5g of Unique in 45 Starline brass w/ 230g Fed. Hydra-Shocks. They are 875fps through the chrono. My gun is a WWI Colt 1911 mfg. in 1918. The gun, though it is old, does not have much wear. I am just beginning to load for this gun. It has been in a safe since the end of WWI. I have changed the spring to a 20# variable Wolf spring. The mags are new My question is. Why is my brass dented on the case mouths? The gun throws the brass forward and right about 5 feet and no they are not getting dented when they hit the ground. I am firing in the grass in my yard (my neighbors love me, hehe).