Maybe give them a call? But my thoughts are whilst it's called a magnum if you can run cartridges with simular powder weight I wouldn't think it's an issue as surely it's same pressures etc?
I was bit nervous running my 22.250 through my 556 one but seems fine, probably put 600 rounds of 22.250 through it, probably 2500 rounds of 5.56 before that.
Bookmarks