M D
I don’t know what the difference is but I’ve had S 99s in 243 & 358 W.
I didn’t have any problems running full throttle loads ESPECIALLY in the
358.
I’ve read a few times about 99s having weak extraction. Maybe some ? I don’t know
but my 358 W didn’t suffer that.
I’d have to check my records but I ran Speer 180 F P and Hornady 200 SP at book velocities.
Jerry
