IMR 4198 & 45/70 in the 1 book 1 caliber reference

[Ray P]

Noticed something that surprised me in the "One Caliber, One book" manual for 45/70:

The IMR 4198 load range listed for a 300gr Barnes bullet in a Ruger #1 matches IMR's load range recommendation for a 300gr bullet in a 1895.

So if I were to load bullets for my 1895 to the levels recommended by IMR, I would be using powder loads Barnes considers only appropriate for a modern singleshot like a Ruger #1.


IMR's  recommendation for a 300 gr bullet in a modern rifle, including 1895:     IMR4198: 45gr to 50.0gr(max).

Barnes recommendation for their 300 gr JFP bullet in a Ruger #1; excluding a 1895:    IMR4198: 45gr to 50.0gr(max).

Am I missing something?

[Redhawk1]

I think you might be. The Barnes bullets are constructed longer and produce higher pressures. If you are loading a different brand of bullet, don't use the Barnes book. I only load my barnes bullets in accordance with the Barnes manual. If I use Speer bullets, I use the Speer manual.  I am going to look at all my books and see if I see what you are talking about.  

[Ray P]

" ...If you are loading a different brand of bullet, don't use the Barnes book..."  

I agree fully about using Barnes data for Barnes bullets.

What concerns me:
The IMR data is saying 45-50gr of IMR4198 is an acceptable load range for any 300gr bullet in a modern rifle, including the Marlin 1895.  Yet Barnes is saying that same powder/weight combo is only safe in a Ruger #1 or similar.  Other listings in the book STRESS that high-end loads for a Ruger #1 are not acceptable for a modern Marlin 1895.  
 
To have IMR recommend loads for an 1895 that Barnes considers unsafe for anything other than a Ruger single-shot or Siamese Mauser surprises me.

[ricciardelli]

My favorite .45-70 with a 300 grain bullet:
Bullet: Sierra 300 Grain Flat Nose Hollow Point
Powder: 51.8 grains of IMR-4198          
Primer: Winchester Large Rifle          
Case: Winchester          
Firearm: Ruger No. 3          
Optics: Leupold 1x4
Velocity: 2161 FPS @ 15' from muzzle
Accuracy: 100-yard, 5-shot, ~ 1-1/2"

Loading range:
IMR-4198 From 31.0 grains to 63.0 grains
 Winchester WLR Primer

[Ray P]

I think I see what Readhawk1 was saying now;  because Barnes bullets are made harder; they will cause higher chamber pressures for a given powder charge over other bullets of the same weight. but lighter construction.

[Redhawk1]

I think I see what Readhawk1 was saying now;  because Barnes bullets are made harder; they will cause higher chamber pressures for a given powder charge over other bullets of the same weight. but lighter construction.

That is exactly what I was talking about.  

[Ray P]

Well, over the weekend I shot through the 35.5 gr to 40.0 gr loads of IMR 4198 under a Hornady 300 gr JHP bullet in my 1895 GG.  

I got very good results with 37.0 & 37.5 gr of IMR 4198.   I still have the 40.5 through 51.5 gr loads to shoot.   I hope to pickup a good higher energy load in addition to the lower energy one I just found.

I can/will refine the low pressure load a bit further by setting up some 36.6 through 37.8 grain loads in 0.20 grain increments.

I also have to improve my bench shooting technique a bit.