During my time with the FBI (1980-2009), I was issued two types of .38 ammunition. The standard issue round when I first started was the 158 grain lead semi wadcutter +P hollowpoints. Later, probably in the early 90's, I was issued 147 grain Federal hydra-shok +P+. This is all I ever carried in any of my .357 magnum revolvers.
Magnum ammunition was generally not carried in the gun, but could be carried for reloading. I was never issued any magnum ammo, but the few guys who were had either Winchester-Western or Federal 158 grain lead semi-wadcutter, non hollowpoint.