There is really nothing magnum about the .32 H&R Mag., unless one is comparing it to the .32 S&W and .32 S&W Long. That doesn't make it a bad cartridge, its just not a super high performance cartridge. It is quite a bit of fun to shoot (and handload for, which is the only reasonable way to feed it). If you want magnum performance, you really need a .327 Federal Magnum chambered gun.
I had a Taurus 327 so chambered, but I never had any luck finding brass or ammunition for the .327 Fed Mag, and I was less than impressed with the quality of the Taurus revolver. I got rid of the Taurus and put a S&W 431 PD on layaway. Hopefully I will be able to pick it up soon. That means I won't be able to shoot .327 Fed Mag ammo, but that doesn't bother me much. I may eventually get a SP101 in .327, or wait to see what else becomes available (I'm really hoping for a SA revolver from Ruger in .327).
Anyway, I chronographed some .32 H&R Mag factory Georgia Arms 85 grain JHP from my 2" Taurus before I got rid of it. Average velocity was 891 fps, ~ 150 ft-lbs of muzzle energy. Nothing spectacular there, but a lot more oomph than the .32 S&W Long. I never managed to break 800 fps with my various handloads using a 100 grain RNFP and various powders, but I wasn't loading max loads either. I have no doubt that performance improves significantly with a longer barrel.