How many different types of ammo are there for a 357 I got 357 mag and 357 sig and neither fits your 357 colt python?

a 357 cal. revolver cartridge WILL fit a colt 357 python. Also, a 38 special will fit a 357 cal. python. The 357 sig cartridge will NOT fit a 357 colt python................

The 357 sig cartridge ONLY fits the sig model pistol

For clarity.....the sig 357 is a pistol. But, the 357 python is a revolver................