Congrats OP, you've acquired the closest gun to a Registered Magnum that you can! The Model 27 is just not exceeded for fit, finish and quality of any S&W's in my humble opinion. Mine shoot any factory ammo but I like the 158 gr myself, and I don't reload.
I've got enough K Frame 38's so if the Magnums go out for exercise, they go with 357 ammo, and usually in a gun rug in a separate range bag.
My small stable of 357 magnums:
Pre Model 27, 6-1/2" shipped 10-16-1952
Model 27-2 Blue, 3-1/2" shipped 4-5-1977
Model 27-2 Nickle, 6" shipped 5-8-1980
Model 28, Satin Blue, 4" HP, shipped 10-13-1975
NOT PICTURED: My Registered Magnum, s/n, reg number, and ship date unknown cause even though 53 years of looking, drooling, close but no cigar... I can't find one I can afford.