[n8ball]

my brother recently bought a trapdoor springfield. i have a few questions about loading for this gun. We quickliy realised that they have a battle sight set up for 250 yards, so he replaced the front sight for a larger one and got it sighted in 1" high at 50 yards using factory loaded blackpowder cartridges with a 405 gr. lead bullet. i loaded 3 loads out of the fifth edition hornady manual using there suggested 300 grain jacketed bullet. He said that the gun had far more recoil with the black powder cartridges than it did with he hornady 300 gr hp and 409 grs of imr 3031 ( the starting load from the manual )
question 1: it is suggested to keep the loads under 29000 psi, the manual says the loads are under 28000 c.u.p. how do p.s.i and c.u.p differ?
question 2: are modern jacketed bullets to hard for the rifling, and if so, are there any suggestions for what bullet, or loads, to use safely? i was looking for an alternative to lead just for a cleaner bore.
question 3: Is there a more specific loading manual for antique/ collectible firearms that may be better suited for loading for the trapdoor?

i know i can do research on the internet, but would prefer first hand experience and knowledge pertaining to this particular firearm.

I certainly dont want to damage it in any way shape or form.
Thanks guys!!

[Hdq]

How do i ask my own question on here? Im using the android app for the forum please help!

[n8ball]

go to the appropriate category and hit new thread

[blitzen25cat]

I reload for my trapdoor. Trailboss is a very good powder to duplicate bp loads. I load a 405gr cast fn over 12grs of Trailboss-keeps it under 1200fps. Best regards Dick

[30-30remchester]

I have heard that most all older guns used softer steel in their barrels since only lead bullets were used. When jacketed bullets became norm, the gun companies had to change the barrel metal to keep wear down. I never use jacketed bullets in older guns. Ken Waters wrote some good articles on reloading the 45-70 in all quises.

[mountainman13]

I've heard of people using 14 grns of unique and 16 grns 3130. I don't understand why people don't just use 70 grns of bp as it was meant for. So what if you have to clean the gun after you shoot? I haven't heard of anyone using jacketed rounds.

[n8ball]

i have ken waters pet loads manual, didnt even think to look there, thankyou. part of the reason i havent loaded bp is i have never loaded with it, and it seems to put more wear and tear on the cases, it also seems that the factory bp loads that my brother tried had a bit more recoil, so i was concerned about pressure.
is there any difference in loading bp than smokeless? or is it the same principals

[mountainman13]

Big difference. The numbers in 45-70 are literally the caliber (.45) and the grains of black powder (70). Black powder is far more forgiving. If you were to accidently load 74 grains of black powder the pressure increase would be minimal compared to if you accidently loaded 18 grains of smokeless which would actually probably be close to double the pressure of 14 grains of smokeless. I've shot a load of 14 grains of unique and it was rather genital. While 16 grains of 3130 whacked the sh!t out of my shoulder. Just as an example say you're loadind a 9mm round and you use 5 grains of smokeless. You could basically subtract your bullet length from Oal (case space) and fill it with black powder and not have to worry about over pressuring. You do have to make sure to clean the gun right after shooting as bp is corrosive.