[Dick284]

If you use prudent reloading procedures when developing loads, it poses no danger.

Prudent reloading procedures are:

- Always use multiple data sources
-Never start at a published maximum load.
-Work up loads from at least 5% off of max in 1/2grian steps.
-Never use data from a unspecified source. ie. some internet data
-Use a chrongraph, relying on primer marks, or flattening is not reliable, neither is sticky bolt lift.
-If any component is changed back off and re work your loads.
-If any lot number on components changes, back off and re work your loads.

In some cases Magnum primers can result in slower velocities and lower pressures, while in other instances the opposite happens.

My rule of thumb is, that if you are going to light up 50gr. of 4350 or slower powder in below freezing temperatures, a magnum primer is worth consideration.
All ball powders should use magnum primers.

Good luck