I'm not familair with a rilfe known as a 227, but in general, no one caliber is "better" than another caliber- they are useful for different things.
Actinium-227 decay to francium-223.
211 223 227.
211 223 227 229 233 239 241
211, 223, 227, 229, 233, 239
211 223 227 229 233 239 241.
-50
211 223 227 229 233 239 241
211, 223, 227, 229, 233, 239, and 241
211 223 227 229 233 239 241.
100-400 USD
211 223 227 229 233 239 241.
211 223 227 229 233 239 241.