The 320 SXG comes with three return springs. Any recommendation on which to use for what.

The Sig website offers some guidance on the recoil spring weights. The internet (such as ChatGPT) also has insights. Grayguns has a recommendation, there is a YouTube on which spring force is best, and a Reddit thread.

https://www.youtube.com/watch?v=lTC0icc-9xo

In general, the recoil spring force is chosen for cartridge ballistics, as well as action timing, reliable feeding, follow-up shot timing, etc.

The pistol came with the orange spring installed, 12 lb one and it works fine with 115 gr ammo. for the curious guy wondering about a "return" spring, it's quite similar to a recoil spring.