The Sig Sauer P250 is a modular hand gun platform that can be chambered in 9mm, .357Sig, .40S&W, and.45ACP. The grips, slide assemblies, barrels and magazines are interchangeable with the the serialized firing group.(step 4) All calibers are also avail. in full compact or subcompact (excluding .45acp). In this instructable I will show you how to field strip this weapon.