Another alternative.
HK USP Full Size -- Not "striker fired" but it is a double stack (12+1) with double/single action and cocked/locked capability (safety can be used or not with hammer down (double action) or hammer cocked.
After thorough research, it appears that the USP 45 is capable of continuous use of 45 Super level loads. My son had been carrying the Glock 20. Neither of us felt/feel comfortable carrying the Glock with one in the chamber, so were looking for an alternative. The USPs “long” double action first shot and thumb safety (if desired) with the .45 Super load fit the bill. Tried the Buffalo Bore 230s and 255s along with several hand loads, finally settling on a hand load using new Starline .45 Super brass and Nosler 230gr JFPs at 1,100 fps. With 12 +1 capacity, it is reliable, portable, reasonably powerful and quite controllable. If anyone is interested, here’ a link covering the subject pistol-forum.com/showthread.php?16503-HK-USP-45-field-pistol.
Still a work in progress and will be testing 250gr LFNGCs (sized .451) from MT Bullet Works as time allows.
https://www.montanabulletworks.com/product/45-colt-lbt-250gr-lfn_gc/FWIW,
Paul