Gauge Magnum

I have a mossberg 500A 12 gauge, and I was wondering if I could use magnum shells in them? I want power!!!?

I just want to have more power for my home defense and fun! If I can’t use the magnum shells, then can I do something to modify my Mossberg 500A 12 gauge to make the magnums work or to get more power and damage from my 12 gauge? I own an LAR-15, which is just like a military M-4 just with out the 3-round burst or fully auto (for the special ops). It’s made by www.Rockriverarms.com and it’s the entry tactical rifle! Please email any answers to DMC2145@yahoo.com Thank you for your time.

if the barrel is rated for magnum it will be printed on the barrel.

Remington 870 Express Magnum 12 Gauge Shotgun