The CCI mag primers are for igniting harder to ignite ball magnum powders. If you are going to use them for non Magnum loads I would reduce your powder charge. Do not load any max loads and you should be OK The have more of a flame and will increase pressure so you need to compensate for that.
It also matters what cartridge you are using them in???
I would guess in a 45 ACP it makes more of a difference than in say a 45 Colt.

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