9mm for sure. Thoroughly clean and lube your new carry piece. Then run 100 rounds through. Field clean/lube (if needed), then run a mag full of mixed ammo. If it doesn't choke then, it's not likely to happen when you really need it. My PM9 didn't need nearly the break in that was suggested. If I'd ran it straight out of the box, maybe it would have.
"Of all the things I've lost, I miss my mind the most." A. Brilliant