There seems to be a lot of debate about the idea lslug barrel and speed but the 25 cal Avenge-X actually does shoot slugs well - I don't have space to go any longer but at 120M, its still grouping well and the pellets struggle. At 50M it puts either one through the same hole 5 out of 8 shots.From my understanding, the Avenge X as not designed to shoot slugs. It shoots Pellets extremely well when you find the one the barrel likes. I guess, that beings it's your gun, you can shoot what you want, but slugs aren't your best option.