I just looked at the Hodgdon Reloading Data Center for loads. I noticed that with a 300 gr. SIE HP bullet, it shows a load of 57 gr. of IMR4064 having pressure of 22,500 cup. My question is, does this seem like a lot of powder? I'm just starting to load for the 45-70, so don't have a lot of experience at this. So far I've used IMR 3031 and ACC 5744. I'm happy with those loads, but just wanted to play with the 4064. any help is appreciated. trapperjim

You are using mor epowder because it's slightly slower than the others you have used. It will liekly be lsightly compressed. I like 3031 in my 45-70 Marlin/1886 loads. I am going to give 4198 a try, good to have more than one choice when it's tough getting hold of powders.

You don't state what rifle you're shooting this ammo from? This could either be a big deal, or just an exercise in academics.

If you're shooting from some "original" rifle, such as a trapdoor, sharps, or rolling block I would use extreme care with some of these Hodgdon loads. I played with some this summer that were supposedly from their "trapdoor" charts that were way too hot in my opinion. I was shooting them from a modern lever action, and from my Contender, and not an original.

I had a fellow AR member run the loads through Quickload, and the pressures given were more in line with what I was seeing than what was listed on the Hodgdon website (and too high for "trapdoor" loads IMO). When I called Hodgdon with questions about their loads, I got the traditional "canned" response that all their loads are tested, blah, blah, blah. The guy didn't even take a second to look anything up, just coughed up the company line.

I would be VERY careful about running some of those smokeless loads through a vintage 45-70.

Stick to BLACKPOWDER, and you'll have nothing but fun with that caliber!

The IMR 4198 loads, and the AA 5744 loads were spot-on with what the book said they should be.

I have been loading some 45-70 loads over the holiday. Yes you haven’t told us what rifle you are loading for. I am using 3031 and varget and some light loads with trail boss.
I am loading for a Marlin GG with an 18” bbl.
I haven’t had time to shoot the varget or trail boss over the crono but the 46.0 gr load of 3031 with 405 cast averaged 1560 fps and is suppose to be good for trap door rifles. I was getting about 1 in at 50 yard.
I would keep in mind that thee factory Remington loads I have are listed at about 1330 I don’t have it in front of me right now with the 405 jacketed fp. So be careful with the old rifles.
Bill

The SAAMI Maximum Average Pressure for the 45-70 is 28kpsi, that's the Hodgdon and Hornady trapdoor load level limit.

http://www.ramshot.com/powders/loadpressure.php

28kpsi = 28kcup in the 45-70

I use 3031 for most all my 45-70 loads, in a Marlin 1895 (full rifle). I could not get the 300gr hp's to shoot at all. A guy I met at the range advised me to use RL7 and it made all the difference in the world. Don't recall the charge weight off the top of my head, but it's in their manual.