Bumping!

Hello All ,
Not sure if this is the right place to post, but I have heard the term "Bumping" to enlarge a cast bullet's dia.
I have about 500 bullets that were sized .358" but I actually need , .359" or larger for my cylinder throats in a pre-27 model S&W .357 mag. These are 18 BHN hardness Is this possible & if so how is it done?
Thanks

yes it can be done basically for a cast bullet you would need a top punch that matched your bullet nose. the inside Diameter of the die would need to be the od your wanting put your bullet in and swage it it will bump up. by squeezing it may be some shorter but will be fatter. Make sure that your bullet is lubed or you will or could loose your lube grooves