45-70 load data from early 90's

[C Younger]

Greetings,

Hope everyone had a safe and uneventful new year. I've been lurking around the forums over the last couple of months, and this place looks like one of the best.

Other than playing with black powder loads in my .44 mag in 2003 or so, I'm fairly new to reloading. I've recently purchased a Marlin 1895xlr and am working on loads for this firearm. I've loaded triple 7 and some H4895 loads with good results.

A friend of mine recently gave me some IMR 4895 (I know this is not H4895) with a sticker on it indicating it was sold in 1993 or so. The can is in good condition, still sealed, and the powder smells good with no rust coloring.

I like shooting trapdoor loads in my lever action for fun, and found a minimum load on Hodgdon's website listing a starting load of 45.6gr under a 405gr lead flat point for 18,900cup.

I've got a Hornady reloading manual Fourth Edition with a copyright year of 1991. The Hornady book doesn't list pressures, but does list a starting load of 51.2gr under a 350gr jacketed round nose, or 45.1gr under 500gr jacketed round nose. Both of these loads are in the (Ruger) section indicating that they are to be used only in very strong firearms, which is where I get concerned.

I've read that powder formulas change from time to time even though they are under the same name, so don't want to rely too much on my new Hodgdon data for this old powder. Does anyone have any loading data from the early 90's that would show an acceptable Trapdoor starting load using IMR 4895 under a 405gr cast bullet that they would be willing to share?

Thanks

 

[DeadEye9]

IMR 4895 is similar to H4895, but a tad slower I believe. I'm not sure about loads from the 90's, but I currently load a low power plinking load in bulk with IMR4895 for my .45-70 lever guns that is also friendly in my trapdoor.
40.2gr is the throw under a 405gr lead. Velocity is around 1340-1350 out of my Henry & Rossi levers and recoil is the same as factory cowboy Type loads, very comfortable. I would start right around 40 and work up until your comfortable. 45-46gr is getting a bit more stout, 1500+fps range.

 

[C Younger]

IMR 4895 is similar to H4895, but a tad slower I believe. I'm not sure about loads from the 90's, but I currently load a low power plinking load in bulk with IMR4895 for my .45-70 lever guns that is also friendly in my trapdoor.
40.2gr is the throw under a 405gr lead. Velocity is around 1340-1350 out of my Henry & Rossi levers and recoil is the same as factory cowboy Type loads, very comfortable. I would start right around 40 and work up until your comfortable. 45-46gr is getting a bit more stout, 1500+fps range.

Thanks for the reply. I had already loaded 46gr IMR4895 under the 405gr bullet believing that it was a starting load. After reading that powders evolve, I decided to check the Hornady book from 1991 and found the IMR4895 loadings under the Ruger section (really wish that Hornady would have listed the pressures). I'd rather shoot the warm loads than pull them apart, but not at the risk of ruining the gun. Do you think that they would be safe. I'll definitely try the 40.2gr as I like slow heavy bullets which is what prompted the purchase of the 45-70 to begin with.

 

[DeadEye9]

I don't think you are at risk to damaging the firearm at that load, even with differences in powder lots from now and then it should still be acceptable as the load manuals tend to take things like that into account. However I wouldn't go any heavier than that until doing some
Test shooting on what you've already loaded and giving a close look at the spent cases and how it shoots. I've run 44.4gr of modern lots of powder in my trap and didn't have any issues, but that's the highest I've gone with that platform. For my lever guns I've loaded much heavier but they are a different animal. Honestly though the trap seems to do better with lower pressure loads in general and I actually get better accuracy with the 40.2gr load and stout black powder loads than I did with hotter 42-44gr loads.

 

[witchhunter]

Well you got it right, this is the best forum on the web. Welcome.

 

[C Younger]

Thanks a bunch. I'll try a couple and examine the brass closely before continuing.

 

[ArchAngelCD]

Examining the brass with do yo no good since you can load the 45-70 to over 50,000 PSI for modern rifles. Powders do change over time but not enough to make the data invalid. If you use the Trapdoor data on the Hodgdon site it is perfectly safe for your rifle. I use that data and other Trapdoor data in an original Trapdoor rifle with no ill effects at all.

Just a note, I used a lot of powders for the 45-70 (over a dozen) until I tried AA5744 and now use nothing else. Under a 405gr Cast Bullet I think there is nothing better.

 

[dh1633pm]

I too use AA5744 now that I have found it, but I loaded many a round with IMR4895. I also tried Unique based on a recipe from an old timer at the shooting range. It was a soft load and intended as such behind a 300 grain lead bullet. Used toilet paper as a filler. The Marlin will take a more stout load than the old time rifles, but I don't think as much as the Ruger loads. So I don't worry so much about going over a bit from the Trap Door data. Not an excuse to forget good reloading discipline.

 

[Don McDowell]

Don't spend a lot of time fretting about the powder, just be sure and stay with trapdoor , or modern lever gun load levels, both of which are covered in your hornady manual, and enjoy the free powder.

 

[C Younger]

Thanks a bunch everyone; now to find some spare time to go give these loads a try. I'll look for some of the AA5744.

 

[fireman 9731]

Also, if you want a soft shooting load, Trailboss is hard to beat. It might be a little hard to find right now but I love it for light loads.

 

[ArchAngelCD]

Also, if you want a soft shooting load, Trailboss is hard to beat. It might be a little hard to find right now but I love it for light loads.

Just he careful with TrailBoss. Pressures can be higher than you think so look for data that will give you pressure numbers just to be sure. IMO SR4759 was so much better. Too bad it's no longer in production.

 

[Jim Watson]

Powders do not "evolve" in terms of performance. The manufacturers may change processes and formulations but 2017 IMR 4895 is as close in "burn rate" to 1993 IMR 4895 as they can make it.
Plus, by using a Trapdoor charted load in a Marlin, you have a large safety margin from the new gun's stronger design and better materials.
Don't worry, go shooting.

 

[Sunray]

"...IMR 4895 is similar to H4895..." Takes a wee bit more IMR to get similar velocities with like bullets. The 'H' burns a tick faster. Only almost issue is that Hodgdon's site only gives cast 405 grain Trap Door loads. Only jacketed 400 grain loads for levers. About 10 grains more too. Like Jim Watson says, you've got a large safety margin using Trap Door loads in a lever. And like Jim says, powders are made the same now as they were in '93. Made to produce a specific range of pressures. Old data will do.

 

[Jim Watson]

Early on, H4895 WAS IMR4895 from WWII surplus stocks. The difference in loads is likely due to the difference in Hodgdon's blend of surplus and what DuPont chose as canister grade. And, of course, Hodgdon went all over for powder after their surplus ran out.
I recall Ed Harris to say there was an appreciable difference when IMR powder went from DuPont in the USA to Expro in Canada. He said it was the change from cotton to wood pulp as the cellulose source. But that was in 1976.

 

[C Younger]

Powders do not "evolve" in terms of performance. The manufacturers may change processes and formulations but 2017 IMR 4895 is as close in "burn rate" to 1993 IMR 4895 as they can make it.
Plus, by using a Trapdoor charted load in a Marlin, you have a large safety margin from the new gun's stronger design and better materials.
Don't worry, go shooting.

Powders do not "evolve" in terms of performance. The manufacturers may change processes and formulations but 2017 IMR 4895 is as close in "burn rate" to 1993 IMR 4895 as they can make it.
Plus, by using a Trapdoor charted load in a Marlin, you have a large safety margin from the new gun's stronger design and better materials.
Don't worry, go shooting.

I wouldn't have thought that powders would have changed much as this would lead to some liability on the part of the manufacturers. It was something that I read in some forums and had heard from a dealer in the area. The dealer told me that any loading manual I had that was more than five years old was pretty much invalid. When I saw that IMR 4895 was only used in "Ruger" loads in the 1991 Hornady manual and in charges similar to what Hodgdon was showing currently for trapdoor loads, it made me start to wonder if powders change more than I thought they would.

 

[C Younger]

I picked up some 5744 and tried the listed low pressure starting load of 24.3 grains under my 405gr RNFP. At first, the price of the 5744 caused me to hesitate, but after realizing that it required much less powder than the H4895 or IMR 4895 for the same performance saw that I was actually saving money. Anyway, thanks for the suggestion. It was a very accurate, fun to shoot, load with light recoil.