Originally Posted by
1blindref
The stamped or folded slide Sigs are still being produced today in Germany for the P225, P228, and P220s. They are mostly being sold only in Germany and Europe. Sig has imported a limited run of the stamped slide P228s with a frame that has a rail on it.
As far as I know, the milled slides are only being manufactured here in the US at the Sig plant in Exeter New Hampshire.
Sig started producing slides that were milled from solid bar stock back in around 1994 when they introduced the P229. They designed the P229 to handle the higher pressures of the .40 S&W and .357sig calibers. The stamped slides were not able to withstand the higher pressures of those two calibers, so Sig went to the solid milled slide design. The P239 came out after the P229 and it was also made with the milled slide.
The change over from stamped to milled slides for the P226 and P220 happened sometime around 1998.
Sig changed the P220 hammers from spurred to the rounded off style somewhere around 1993. Your gun with the European style mag release was probably an over run military or Police contract gun that Sig exported to the US.