When SIG first came to the US in the mid 1970s, the P220 was introduced in the .45ACP format. Once it started to gain a following, it was also brought here in 9mm and 38 super. The P220 was also manufactured in 7.65mm Luger in Europe, but there was no interest in that caliber here in the states. The 9mm has long since been discontinued, and the 38 super, more recently bit the dust. As Pistolenschutzen said, the P220 is only offered in .45ACP today.
Law enforcement wanted a higher capacity 9mm pistol, which resulted in the P220 getting reworked into the P226 as a double stack 15 round handgun. The P226 as well as the P220, continue today, as a pair of the best quality firearms, in their format. Well, in my opinion anyway.
Sorry, hope you enjoyed your shower.