Here is a photo of the pistol. It has a standard Belt Mountain base pin, with a screw to keep it tight. This is the one issue that I have had with Rugers. The base pin likes to pop out. It has the regular aluminum grip frame, and aluminum extractor housing. Some folks agree that the aluminum frames help keep the screws from working loose on both. I have had the ejector housing screw to loosen on steel housings, but, never the grip frame.