Question about ammo. What are all the types of ammo you can run through a smith Wesson mp15-22? I know .22LR but there are so many different variants. I know from the manual to NOT use Remington ammo and any subsonic ammo. Also, can I use .17HMR???? I never heard of it but seen them at wal mart and wanted to buy them but didn't think I could use them.