Agreed on pumpers, to me they're the most practical overall! Also a multi-shot magazine increases independence.
I haven't been into airguns in a while, just getting back into it all. What sorts of mods are done to the carbine? Looks very good. Similar to something I could use to eradicate the pesky ground squirrels around here. The ground looks like an 'After' shot of a mine field when they're done with it, plus their destruction of vegetation.