Re: H&R 32 Cal
this is a case where i will disagree with the other two answers. smokeless powder loads should never be used in any firearm designed for blackpowder cartridge pressures regardless of the caliber. you may not hurt your self doing this but you will hurt the firearms by causing undress stress on the frame and parts. basically you will turn a nice black powder cartridge era firearms in to a junker not even good as a parts gun (put another way you wil turn a $100+ gun into one not worth $20).
now for the revolver in question. H&R manufactured two top break model in 32 caliber. the large frame auto-ejecting and the small frame premier. in 32 caliber the small frame priemer held 5 rounds and the large frame auto-ejecting held 6 rounds.
the small frame premier model H&R was manufactured between 1895 and 1941. there were two models first model 1895-1904 designed for black powder cartridge pressures only. second model 1905 to 1941 designed for smokeless powder cartridge pressures. the only outwardly change in the two models and the feature that you can use to tell the difference in the two models is the markings on the left side of the barrel. the first model only has markings on the top of the barrel while the second model will have either the model name or caliber (sometimes both) marked on the left side of the barrel in addition to the marking of the top of the barrel.
the large frame auto-ejecting was introduced in 1885 and there were three models first= 1885-1889, second 1890-1904 and third 1905-1941. like the small frame only those made after 1905 (third model) are considered safe with modern smokeless ammo. in the large frame auto-ejecting model it is the third model that has the markings on the left side of the barrel.
with out knowing which model you have here is my best guess;
small frame premier, second model manufactured between 1913-1924.
large frame auto-ejecting third model manufactured between 1910-1913
which ever model this revolver is it is an early smokeless powder revolver and if in good condition otherwise it should be safe with modern factory standard velocity ammo.