Can use my.40 for my 10mm?

[Hoser]

.400 diameter bullets work in any .400 cartridge.

. Only thing that I would not do is load plated bullets into 10mm due to its power

Where on earth did you hear that? Plated bullets pretty much suck at most all pressures when you are looking for accuracy.

The last thing I would use in a 10 is lead.