It is a 177 mate it's a BSA r-10,I'd be lying if I said I shot them all with this gun,it was a joint effort between me and a mate,but both guns used were 177 shooting at around 11.4 ftlb.
Most of them were shot at ranges between 25 to 35 yards,the long shot being a bit of a one of for our shooting skills.
Depending on distances your shooting mate really when you say about live round or airrifle,you can't go wrong with an air rifle though for shorter distances.