CCI small rifle magnum primers burn a bit hotter for a bit longer. They’re made to light hard to ignite powers and for extreme cold weather shooting(some powders get hard to ignite in the cold). You don’t need them for either of those powders. If your manual says to use them, do so, but they won’t hurt anything if it doesn’t. CCI small rifle magnum primers
hold up better…” No. The only difference between it and a standard primer is the priming compound.