In 2007, a Picatinny rail was added to the body under the barrel as regular on all versions whose number ends in R. The main change in slide design and style, between the more mature design SIG pistols and the current production, would be that the more mature model slides https://sigsauerp220elitedarkfors23445.win-blog.com/6667325/sig-p220-legion-10mm-holster-things-to-know-before-you-buy