231 VS 296 VERY DIFFERENT powders - for different performance levels. For your 357, if you shoot mostly target and plinkin then use the 231. If you want top end power level then use the 296. One thing to remember, 296 is not to be used for reduced loads as SERIOUS issues can result.

Always carefully follow the reloading manual recommendations.

I shoot a lot of 296 in my magnum cartridges with very good results and I also use 231 in the good old 45acp with exceptional results.

ward