The .45 ACP is the best semiauto cartridge for bowling pin shooting.
It doesn't recoil so much that it can't be shot fast and the 230 grain
bullets get the pins moving off the table. Of course, as Rich Davis wrote, you have to hit "the white part" of the pin (the middle.)

I have shot pins with the .41 Magnum as well. It takes them down
with more authority but I often end up needing a seventh round and
not having it when using the .41.

The old .45 is also one of the easiest cartridges to reload, and to make
accurate loads for.