45-70 loads with N32C(tinstar)

[marlinleverman]

I have a Marlin 1895 45-70 and have some Viht N32C on hand. I'm looking at Viht site but they don't list anything for this powder, any help or info would be greatly appreciated. Thanks again.

[NSB]

https://www.uslapua.com/ProductDetai...uctCode=VN32C1
Viht isn't providing loading data for this. According to Laupa, who now handles it, they only give data for 38spl and 44mag....odd. I think you're a lot farther ahead to look at Trail Boss.

[Finn45Colt]

http://www.vihtavuori.com/en/homepage.html

VV don't give any data for rifleloads with pistol/handgun/shotgun powders. Burning rate is somewhere between red and green dot, for VV between N320 and N330.

[17nut]

You are a hard man to help given that you dont state bullet weight!

Tinstar and Trailboss have very similar burning rate and energy but Tinstar is less fluffy.
Where Tarilboss says 70% volume starting point the number for Tinstar is 50%.
So measure the volume in the case with the bullet you intend to use and start at 50% filling.
Never ever ever ever go past 100% and start compressing the load, the pressure curve is like a hockey stick and goes skyhigh fast.

[marlinleverman]

Thank you for the information.

[NSB]

Just something to consider: this powder is about impossible to find and it's very expensive. I wouldn't dedicate the time and effort into finding a good load with it only to find you can't get any more of it to use afterwards. I've gone down that road in the past and looking back, I wish I hadn't.

[marlinleverman]

Good point, I have 6 lbs on hand. I have H4198 and AA5744 also, saw another thread on site where a Gent did some extensive testing with N32c in a variety of Cartridges. I use it in .38 special and 45 Colt and thought a light recoil load for 45-70 with 300-405 gr bullets would be nice to have.

[Larry Gibson]

I did a very comprehensive test Of pressure, velocity and accuracy for an ammunition manufacturer and the VV rep for the use of N32(C)/TinStar powder for use in cowboy action loads. That test included the 45-70 cartridge.

Be aware that Tin Star powder has a burning rate faster than Unique and I do not advise on a "50% rule" in large cases such as the 45-70.

The 45-70 test I did used a hard cast commercial bullet purported to be 405 gr but actually weighed 413 gr. I worked up to 15 gr of N32(C) which gave an average pressure of 28,500 psi(M43). Out of the test rifle's 24" barrel the muzzle velocity was 1132 fps. The ES and SD for both pressure and velocity were extremely good. The pressure traces exhibit a very sharp rise to max psi. Thus I loaded 14 gr N32(C) under the same bullet for the accuracy test using my H&R Officer's Model with 26" barrel. The tang rear sight was used. The muzzle velocity for the 14 gr load was 1086 fps out of the OM and the 10 shots went into 1.222" at 100 yards.

I expect to conduct further testing with 300 and 350 gr cast bullets as my opinion is this is really too fast a burning powder for bullets heavier than 415 gr. It should do very well with the lighter weight bullets. It also is not a powder to develop top end velocity with.

Attachment 211710

[NSB]

Good point, I have 6 lbs on hand. I have H4198 and AA5744 also, saw another thread on site where a Gent did some extensive testing with N32c in a variety of Cartridges. I use it in .38 special and 45 Colt and thought a light recoil load for 45-70 with 300-405 gr bullets would be nice to have.

I guess if I had six pounds of it I'd give it a go. That's enough to keep you busy for quite a while. I often see someone asking this type of question when they have a pound of powder and get overly engrossed in trying to use it. With an adequate supply it's worth the effort. Good luck.

[marlinleverman]

Thank you Larry, it was your post on the other thread that I was referring to. If I choose to try this N32C in my loads I will heed your advice. I would think a 405 gr Bullet at 1000-1100 fps would work nicely.

[marlinleverman]

Thank you NSB for the information and help.