SJS, I am loading 13.5 under the 158 XTP as well. I use this load in 4 different revolvers. I have used CCI 500, Win SP, and Remington 5 1/2 (magnum) primers after working back up to 13.5 grains. While all three provide similar results, the Remington 5 1/2 primers work the best accuracy wise for me.