on all models whose number ends in R. The major difference in slide design, between the older model SIG pistols and the current production, is that the older model slides were stamped whereas the current production models are milled on a CNC machine. The stamped models have an end piece at the muzzle end which is welded in place, to complete the slide. Additionally, the older stamped slides feature a removable breech block. This breech block is pinned to the slide with two hollow roll pins, one pressed inside the other, with their split ends opposed. The newer milled slides are a one-piece unit and do not have a removable breech block. The SIG P220 also comes in P220R and P220ST versions. Also in 2019 a new variant is available called the P220R Hunter that is chambered in 10mm and factory coated with a KRYPTEC camo pattern. The base and R models have an aluminum alloy frame with a stainless steel slide (if made by SIG Sauer in the US; German made versions still use a blued, stamped steel slide); the ST model has a stainless steel frame and slide. The R and ST models also have a Picatinny rail, beneath the slide and barrel, allowing for fitting of accessories such as lights or laser sights. Originally, all SIG P220s were DA/SA and featured a decocking lever (and no external safety) just forward of the slide catch. This changed with the introduction of double-action only (DAO), Double Action Kellerman (DAK), and single action (SA) models. The DAO and DAK models do not have a de-cocking lever or safety, and the SA models only feature an M1911 style external safety. SIG has also introduced the SAS (SIG Anti-Snag) model—which is dehorned, has no accessory rail, and is designed for concealed carry—and the Elite model, which includes the new short-reset trigger, a beavertail grip, front strap grip checkering, and front slide cocking serrations. All modern P220 variants are available in .45 ACP and, as of January 2015, 10mm Auto. Browning BDA (early American import) The P220 was initially imported to the United States as the Browning Double Action (BDA) and then as the Sigarms P220. The P220s sold under the Browning Arms Company marque in the United States c. 1977–1980 had the heel-mounted magazine release lever until Browning discontinued it from its product line in the early 1980s; the discontinuation from the