My favorite load for my 686-6 is 158 gr Hornady XTP, over 13.5 grains of 2400, in Starline brass with CCI 500 standard small pistol primers. I estimate this gives me about 1175 fps out of my 6 inch barrel.

I am getting low on primers and went to my LGS and they were out of standard primers but had some CCI 550 magnum small pistol primers, so I got some.

I expect that substituting magnum primers will change the velocity and perhaps the accuracy, and I can adjust for that but I am concerned about the safety of it. None of my loading manuals show magnum primers for the .357 loads.

My load is well below maximum, which my manuals show as 14.8 grains. I would think that my load of 13.5 should still be safe with magnum primers but I don't know for sure.

Any comments will be appreciated.