I shot IHMSA production class with a .357 Maximum in a 10" TC Contender for a few years,.. almost all of it with cast bullets.
I had a chronograph back then and was very surprised with the velocity that I could get with the cartridge.
Most of my shooting was done with the RCBS 35-200FN bullet made from straight quench cast wheel weights. I got very good accuracy with H4227 at about 1550 with that bullet (which weighed about 220 grains cast from wheel weights) and on a few occasions, I took that 220 grain bullet close to 1700 fps with WW680 back when it was still available,.. and bear in mind,.. that was from a 10" barrel. The primers showed no sign of excessive flattening and the cases would slip right out of the chamber after firing. In other words,.. there was no sign of excess pressure at that velocity with the WW680.
It seems that most people chose bullets intended for the .357 Magnum when they load for the Maximum,... but it really shines with the heavier bullets intended for the .35 caliber rifles,... especially if they're cast bullets.
I'd say that a Handi chambered in .357 Maximum would be something worth having.