I had a thought about the SR's and I am pleased to say it worked great ! I have a SR9c in 9mm Luger. I thought that the Ruger company would not have much for changes when doing the 40S&W so I got onto Gunbroker and bought a parts kit that had everything for a SR40c except mags and plastic frame. I gambled that the ejector would work or be the same for each caliber. Pleased to say a booming success. All I had to to was put the 40 top onto the 9 and use the appropriate magazine. Point of impact is controlled by the slide, so no issues. Shot 50 rounds of each caliber with both short and high capacity mags and narry a bobble. Worked flawlessly. Now I can have the more powerful 40 or a 9 with a couple extra rounds. All the kit cost me was $148 plus some mags. On GB there was a seller in CT that had THREE high capacity 40's for only $30 plus $12 shipping. That's only $14 per mag. The short ones are available even on eBay as they are 10 or less rounds. I am now a big fan of this pistol as it has the safety trigger as well as a thumb safety. It also has a mag safety that is easy to remove if desired. If it is dry fired much without a mag inserted, it will damage the striker assembly. An idea that others might want to try as it is so easy and inexpensive. Hope this info helps, Neil aka Ruger44fan in Maine.