Anyone have any data regarding Accurate Arms MR 3100 powder and load for a 45-70? Picked up some powder at a gun show and was told it works well for 45-70 but I can't find any published data for it. I'm looking for a powder weight or range to start some load experiments.

Thanks in advance.

According to their reloading manual, a start load for 340 gr.L HP bullet is 54gr of 3100, max. is 60.0gr. compressed. For 378 gr LRNGC bullet, start load is 50.4gr. of 3100, max. is 56.0 gr. For 420gr LFN bullet, start load is 54.0gr. of 3100. max. is 60.0 gr. compressed. These loads are stated as safe for Trapdoors. If you are shooting a Ruger, Marlin, Sharps, etc (modern steels) then the start load for a 378 gr.L RNGC bullet is 54.0 gr 3100, max. is 60. gr. For the 405 gr L FN bullet, the start load is 54.0 gr 3100, max. is 60.0gr. If you are shooting heavier bullets, let me know and I can send you that info. Emery

The book also suggests a firm crimp. Emery

Thanks Emery,

I should have been more specific. I am loading for my Marlin Guide Gun and I am using the Hornady 350 grain RN jacketed bullet. The data is very helpful.

I use the Redding Taper Crimp Die on the 45-70, always firm.

Thanks again.

OK, The Accurate manual lists 58.5gr of 3100 as a start load for the Hornady 350gr RN bullet at a velocity of 1399 fps; with 65.0gr of 3100 (compressed load) as max with a velocity of 1590 fps. Emery

OK, The Accurate manual lists 58.5gr of 3100 as a start load for the Hornady 350gr RN bullet at a velocity of 1399 fps; with 65.0gr of 3100 (compressed load) as max with a velocity of 1590 fps. Emery


Thanks again, can't get any more precise than that. Did they say anything about the type of primer used to collect the data? I will use either a Win LRMP or a CCI 200.

Yep, Douglas 24" bbl., WLR primer, WW case, OAL max. 2.550", min. 2.530.

Thanks, the data suggests the MR 3100 powder might be a little milder load than what I am used to. I have about two pounds of powder to shoot up. I'll post my results.