There's no competition here, the 50 cal is better.
It's semi auto whichmeans its better in close combat, it's really powerful, it looks cool, and it doesnt take a year to load. It also doesn't take up half of the screen when it's loading.
its a close race to me.. but the ptrs has less recoil IMHO.. i can typically recoop from the recoil and fire another accurate shot faster with the ptrs