40 sbn

[bobw]

18-20 I'd say is probably correct, Mine is 1 in 18. I won't say 400 gr bullets weren't used back then but not like the 400+ gr ones used today which mandate a 1 in 16 as well as tighter twists. Both the 40-70SBN and the 40-700ss Utilized the same 330 ppb as a std factory load from what I've seen. A 370 gr ppb was std in the 40-90 SBN and was reputed to be a much better killer on buffalo. If a guy has a 40-70 SBN with one of today's chamber that is large enuf to seat a .408" groove dia greaser in it ,all is not lost. FL size the 1 st loading to fire form the case. After that just deprime, clean ,dry, reprime, Make sure the inside of the neck is clean and shiny, charge with Fg thru a drop tube Half the way up the neck, insert a hard card and compress the load to the neck/shoulder juncture no deeper. Lube wad, another card wad at this point put the assembled rd in your press and screw in a 40 S&W tungsten carbide sizer die and size down the neck to hold your .399/.400" patched bullet. That's right your patching to bore dia . I have had zero good results trying to patch to groove with my rifle in this 40-70 bn config. bobw ???????