I don't mean to hijack the thread, but it seems like the original question was well answered.
I inherited an 1873 Springfield trapdoor about 9 months ago. It's pretty weather worn, and took a lot of TLC to get it back to a state where the rifling was visible. Regardless metallurgicaly speaking. it's a little rough, sort of a bumpy surface over the whole outside of the barrel. However, I took it to a gunsmith (pro-shop owner of a local range) who eyeballed it for a few minutes and said "yeah should be fine, just go easy on her, but I see no need for you to use black powder"
I am a newbie to reloading, been reloading .303 Brit for about 6 months. So, straight cases are something new. I have IMR 4350 and 405 cast balls, and some once-fired cases, and some I believe to have never been fired (super clean, no primers)
My overall question is, in a old dog of an 1873 trapdoor, would it be safe/advisable to load the above mentioned 54 grains of IMR 4350. If not, what would you suggest?
