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45-70 loads?

Posted: Mon Jun 08, 2020 10:18 am
by James84
does anyone have any recommendations for a 45-70 load using 10x in PPU brass under a cast 405gr RNFP from Shellhouse Bullet Co.?

It is going through a Marlin 1895. I took it out this weekend with my initial handloads which I think were slightly too light and the groupings were awful. I tried 39gr. The Alliant website only covers up to 400gr FNSP and I have read somewhere that someone recommended 41gr 10x under a cast 405gr RNFB. I know the 1895 isn't a 'target rifle', but from what I've read online, I can expect around 1.5-2" at 100yds from it, some people claim to get better, but I'm not expecting to from a 18" barrel. However, I was getting more like 6-12" (using an optic as well).

Would anyone know if 41gr would work better? I know that Unique and RL-7 apparently work better, or so I have read/been told, but I only have access to 10x at the moment.

Re: 45-70 loads?

Posted: Mon Jun 08, 2020 10:35 am
by FredB
American powder manufacturers loads are usually for hunting, not target work. Your loads are probably much too powferul for what is needed at 100yds. Get yourself a Lyman cast Bullet Handbook.
Fred

Re: 45-70 loads?

Posted: Mon Jun 08, 2020 11:25 am
by dodgyrog
I'm using Viht 120 behind a soft'ish cast lead boolit. Nice and accurate in my Ruger No 3.
I hope you don't have microgroove rifling!!!

Re: 45-70 loads?

Posted: Mon Jun 08, 2020 11:30 am
by James84
thanks for that, I do actually have some 120 in the cupboard, I'll do some reading! Do you find it accurate? No microgroove rifling :D

Re: 45-70 loads?

Posted: Mon Jun 08, 2020 12:32 pm
by FredB
Microgroove rifling is better for lead bullets----see .22 target rifles!
Fred

Re: 45-70 loads?

Posted: Mon Jun 08, 2020 2:37 pm
by dodgyrog
FredB wrote:Microgroove rifling is better for lead bullets----see .22 target rifles!
Fred
Not in my experience Fred!

Re: 45-70 loads?

Posted: Tue Jun 09, 2020 6:52 pm
by andrew375
The reason why micro groove barrels have a reputation for less than stellar accuracy with cast bullets is that they all seem to be oversize. Cast bullets have to be at groove diameter or more to shoot well. I've slugged a few Marlins and they were all at least a thousandth over nominal size, might not seem much but that is all it takes. My 1895 was. 4595" and so was hopeless with .458" bullets. In the end I made a mould that cast out at .461" and made a sizer to just touch the sides, the rifle magically started making sub 2" groups at 100 yards. The problem with commercially cast bullets is that they come sized at the nominal diameter, which usually turns out to be too small.

Re: 45-70 loads?

Posted: Tue Jun 09, 2020 8:06 pm
by FredB
----and they are too hard and will not upset in the throat to fill the grooves.
Fred

Re: 45-70 loads?

Posted: Tue Jun 09, 2020 11:46 pm
by bradaz11
Sent the info to you from cast bullets handbook v4