If you read this blog much, you'll note that it looks an awful lot like my .38 Super Witness. That's because it is my .38 Super Witness - mostly. I bought a .40 S&W conversion kit for it, plus six spare magazines (for a total of seven). The conversion kit I bought direct from European American Armory. The magazines I bought from U.S. Citizen. I also bought 1,000 pieces of once-fired brass and 1,000 Berry's 180 grain HP plated bullets. I thought about buying a 10mm conversion, but the cost of brass decided it for me. .40 S&W is ubiquitous and cheap. 10mm, not so much. Everything's here but the bullets. I may have to break down and buy some factory fodder for a test this weekend.
It looks like the .40 will be MUCH less picky about what it eats than the Super.