For an interesting bit of data, somebody with a loose GP11 bullet should measure the diameter below the cannelure groove, and above it.

You will observe something unusual.

To my knowlege, no other bullet has that.

They do it for a reason. (What? Heck if I know -- I have some guesses, but they're just guesses -- the Swissicon do everything for a reason and are rather proud of not copying anybody else).

I don't bother to handload GP11. At 52 cents a round, delivered, not too long ago, I stockpiled. I can't reload for that price.