Combat The two "Combat" models, the P220 Combat and P220 Combat TB (Threaded Barrel), are available in DA/SA only. Their frames are colored "Flat Dark Earth" in compliance with the Combat Pistol program. The Combat model comes with night sights, a Nitron-finished slide and barrel, phosphated internals, and a Picatinny rail. The TB model features an extra 0.6" on the barrel, and external threads to accept a suppressor. The P220 Combat is chambered only in .45 ACP, and is supplied with one 8-round magazine and one extended 10-round magazine. P220 ST A version of the SIG P220 handgun made by SIG Sauer with a reversible magazine release, stainless steel slide, and stainless steel frame. Changing to a stainless steel frame from the lighter alloy frame normally used is meant to reduce felt recoil. The ST models are typically bare stainless (all "silver"), though SIG Sauer has produced Nitron finished (all "black") ST versions for police department trial and evaluation (T&E) guns. P220 Classic 22 This model's primary purpose is as a practice or range pistol. The Classic 22 model replaces the typical stainless steel centerfire slide assembly with a lighter aluminum rimfire slide chambered in .22 LR. The Classic 22 also has a different barrel, guide rod, and recoil spring than the larger caliber models. It incorporates the same frame and operation as centerfire P220 models. The Classic 22 model is available as a stand-alone firearm or as a conversion kit to an existing centerfire P220. Likewise, conversion kits (the SIG Sauer X-Change Kits) exist to convert a .22 LR P220 into .45 ACP. The conversion can be accomplished by field stripping the firearm and replacing the slide assembly and magazine—a process that can be accomplished in minutes. The Classic 22 use a 10-round polymer magazine in lieu of the steel magazines used by the centerfire models and conversion kits. The P220 Classic 22 should not be confused with the SIG Sauer Mosquito .22 LR pistol. The Classic 22 is a full-sized P220 while the Mosquito is modeled on the P226 but is 90% of the size. Another difference is that the Classic 22 is manufactured by SIG Sauer while the Mosquito is made under license by German Sport Guns GmbH. The size difference means that the Mosquito cannot be converted "up", and full-size SIG Sauer pistols cannot use the Mosquito's slide assembly. P225 / P225-A1 The SIG P225 is