I have designed a DI/gas operated pistol cal uppers in 45acp, 40S&W, 7.62x25Tok & 10mm. The 357 sig is next along with the 9x25. They run on stock lowers unless you reload light then you may need a light buffer.

Here is a video of me running 20rnds of Rem 230HB through one of my uppers, Enjoy