Proper fit is important
I have a Buffalo Classic 45/70 that won't shoot any cast without leading. Same for my 30-30 single shot. Leading should be simple to remove. I use #0000 steel wool with the fibers pulled out very thin over a wet snug patch. Even better for the bore is bronze wool if you can find it.
Pro-Shot Products ,PO box 763 ,Taylorville ,Illinois 62568 (217) 824
-9133 makes a lead-clean gun cloth. Cut off a small patch and it will pick up the lead in 2 or 3 passes .
Both of the afore mentioned rifles shoot jacketed with no problems at all.
I just got a vintage Marlin 1963 336 30-30 that shoots 170 grain Oregon Trail gas checks without a trace of leading.



It is my limited understanding that most all leading is a result of bullet to bore fit is off .
Sure hope you get by without the bore leading. I have just learned to live with the 45/70 leading. I can get around 20 shots at clays tossed on a berm 110 yds out before the leading fouls my shots. 15 min. at home and bore sparkles again. Sure gets fustrating though.