What's your preferred tool(s) and process for reshaping a Mauser magazine follower? I'd like to slightly increase the width available for the bottom cartridge's shoulder. It's chambered for 338-06AI, and will only hold 4 in the magazine now. I can get back to the 5-down configuration with just a bit more room at the bottom of the stack I think. I'm a little hesitant to just put it on the grinder.

I use an old Sears flex shaft grinder with a 1/2" drum with various grit sleeves. Works very well. I've done Brno/CZ and Win Mdl 70's. No Mausers but should be no difference. Tried using mounted stones but abrasive sleeves work best for me. Then engine turn and it looks nice.
I have only ground the followers to make the last round feed straight in not to increase capacity. First saw it on a David Miller rifle
and copied it.

Magazine width at the shoulder is probably too narrow for the larger shoulder diameter of the Ackley improved cartridge.

Think 4 will be your max,so that gives you 5 shells. one in the chamber plus 4. van