Lots of folks don't really get the issue of spring balance in 1911-types. Slide velocity is primarily controlled by the mainspring, not the recoil spring. If you use a full-strength mainspring (23 lbs.) you can get by with a lighter recoil spring than if you use a lighter mainspring. Basic, John Browning/Milspec setup is a 23 lb. mainspring and a 16 lb. recoil spring, though lots of commercial Colts have had 17lb. recoil springs. One pound doesn't matter very much.

Lots of gunsmiths install a 17-19 lb. mainpsring, mostly to make it easier to obtain a light trigger. The 18-18.5 lb. recoil springs that are so often recommended for "hardball equivalent" loads presume a light mainspring.

One can install an EGW flat-bottom firing pin stop and get by with both a light mainspring and a lighter recoil spring, since the EGW stop delays unlocking a bit and thereby retards slide velocity some. I've learned much about spring balance converting 9x19 1911-types to 9x23. In my 3" Ultra Aegis conversions, I use a 25 lb. mainspring, an EGW firing pin stop, and the standard Kimber .45 recoil spring assembly (about 21 lbs.). In the 5" Aegis guns, I use the EGW stop, a 19-21 lb. mainspring and an 18 lb. recoil spring.