.357 brass is slightly thicker/stiffer, so it may not maintain a consistent crimp for as long as .38 brass. For target loads, .38 cases are more than adequate (and a lot cheaper), so I'd suggest using them unless your lever-action cycles more reliably with the longer case. Popular wisdom is not to put very light loads in .357 cases because of the larger case volume (risk of detonation?), but I've never heard of any specific issue in this respect.

I use 2.5gns BA10 behind a 158 T/C hardcast bullet in my .357 Taurus using a .38 case. 2.7gns of CSB5 also works well, and CSB5 is easier to source than BA10 these days.