Smith&Wesson has their Scandium pistols. I have a 329. A 44 Magnum at 25oz. Extremely light weight. I bet a 1911 could be made at 20oz. However, felt recoil increases with lighter weights.
With a new sidearm in the works, if it doesn’t come out as a .40 Cal, there’s going to be a lot of surplus ammo on the market since the gubmint bought millions of .40 cal rounds a year or so ago.