SIG Sauer P320 Pistol Magazine, 20rds, 2 Pack 20rd magazine 2 pack For .177 pellets NOT compatible with the SIG Sauer M17 or P320 Spectre Comp Blackout CO2 pellet pistols Please Note: We are aware Sig Sauer product pages state these are 30 round magazines. They are not, and in fact are 20 round magazines. These magazines are not compatible with the M17.