Once upon a time there was a game called Metal Gear Solid (1). It was this game that inspired me to make these modifications to my KJW Sig P226 (and only because a MK23 SOCOM pistol is a headache to own and upgrade).
1) Threaded outer barrel.
2) Mock suppressor.
3) Extended 1911-length inner barrel*, which nicely fits the extra outer barrel length offered by the threaded outer barrel.
4) Teflon recoil spring guide for smoother action.
5) Just the right amount of silicon oil.
The result? A pistol that looks cool but makes a hollow-tube noise when you rack the slide or shoot. Still worth it because of the looks though.
*Note: I do no recommend using a full length inner barrel with this gun because I found that it interferes with the cycling of the gun (preventing it from locking back and increasing wear on parts).