Since the topic is about .357 Maximum, for those who might know more about it than I, what is it that .357 Max was advertised to do that .357 Mag couldn't? Okay, throw a heavier bullet faster, but when did that really do anything well enough that it could replace a larger caliber like a .44
Yes - the .357 Remington Maximum was introduced to "legitimize" the grossly overloaded .357 Remington Magnum loads being used in the Metallic Silhouette matches.
The .357 Max throws a 158 grain slug at (a claimed) 1800 fps. In order to achieve that velocity - you need to exceed SAAMI levels for the .357 mag by 5000 psi (.357 mag = 35,000 psi ---.357 max = 40,000 psi)
Normally - muzzle energy is a moot figure - actually - any "energy" claims are moot - they simply don't have much merit. (Please - no discussion here about that - please open another thread for that topic)..
HOWEVER - once in a great while, even a blind squirrel finds a nut & a use for downrange energy levels pops up...
The very flat shooting and fast scooting 158 grain .357 max - has a whopping 1100 foot pounds of energy at the muzzle & @ 200 meters (the distance to the Ram target in Silhouette) it still has enough authority to knock over the target. In Silhouette - unless the target falls, it's not scored as a hit.
IIRC - the "sweet spot" for the .35X on the Ram target is about the size of a couple of post cards, high on the back of the target. It takes a lot of oomph to topple the target with a small caliber like the .35X.
OTOH - the .44 mag & "juiced" .45 Long Colts - using a much heavier slug, had no problem generating enough energy at 200 meters to knock the target down.
The .357 and the .44 & .45 competed in different classes.
So - the .357 max and the .357 mag competed head to head.
Anyhow - to answer your question - the .357 max, can
accurately throw a heavy bullet faster and flatter than the .357 mag.
Can you push a handloaded .357 mag to the same velocities? Probably. I sure would try it in anything other than a Freedom Arms, an older Dan Wesson and/or a Ruger Redhawk - or a T/C. You are asking for trouble if you do.
Trying to stuff the amount of power involved into that small case is nothing short of complete idiocy.