Chamber Pressure Rating for .45-70 Single Shot

[Cooper]

I understand that I should use the Marlin lever action reloading data listed in the Hornady book and not the Ruger No. 1 load data. With that being said, does anyone know what the chamber pressure rating is for the single shot .45-70, H015-4570? Hornady's book indicates that they keep the pressure below 40,000 c.u.p. for the lever action.

Since the Henry single shot is not a lever action rifle, I would like to know if it can handle greater pressures.

I called Henry and customer service said that it is built to SAAMI specifications, but cannot locate this information.

Believe me, I don't want to use maxed out loads, my current bullets going 1,800 fps are enough, I just want to know my limitations.

Thanks!

Cooper

[clovishound]

Perhaps this will shed some light. It does not give the definitive answer, but may help some.

https://hsmammunition.com/faqs/

Click on the link for what firearms can I safely shoot your 45-70 bear load from.

The last three sentences explain the three types of firearms and the three max pressures for them.

[North Country Gal]

Good question and one that I've had, myself, a time or two with other guns. The problem is that manufacturers can never recommend straying from SAAMI specs for the sake of liability and possible litigation. Most of them won' even supply max pressure ratings for the same reason.

And keep in mind that there is more to it than raw pressure ratings for various actions. A good example is the original Contender single shots. TC actually rated the Contender at 45,000 psi and the Contender was chambered in the 4-70. What we learned, real quick, is that pushing the 45-70 up to those kinds of pressures in a Contender led to stretched frames and ovalized hinge pin holes. Same thing when people started reaming out 44 mag Contenders to the 444 Marlin. The problem wasn't just the pressure. It was the large case head size pushing back against the frame at those pressures. In other words, it's not as simple as just pressure.

The Encore is stronger and is similar to the Henry single shot. (TC never gave out pressure ratings on their single shots after the Contender). I know folks who have pushed the 45-70 in an Encore up to Ruger No.1 pressures, but not without some issues. As for me, I won't push my Encore 45-70 that far, no way. Lever gun loads are all I care to to shoot as far as recoil and performance.

[Cooper]

Thanks for the comments.

As I stated above, I have no plans to come close to 40,000 c.u.p., but as I explore the best combination of powder and bullet for my rifle, I want to know the rifle's limitations and stay well under that amount of pressure.

[tarbe]

North Country Gal...you continue to shine.

I was going to reply with much the same post...but you got it covered!

To the OP; if you backed me in a corner and asked me which platform would I rather shoot a steady diet of 40k CUP loads in...a Marlin/Henry lever or the Henry Single Shot, I'd take the single shot.

But as you clearly know and have as much as said, the Henry single shot is no Falling Block Ruger...so don't try to get 2,000+ fps with 400gr in the Henry!

My 45 years of playing with the 45-70 has taught me that it is one stellar killer....and you don't need to hot rod it for woods hunting. Shot placement is still the key!

Have fun, be safe.


Tim

[clovishound]

My buddy was expounding the other day about the most effective bullet for 30-06. I made the comment that, given the game I am going after here in our area, any 30-06 round going to be overkill anyway. He agreed.

I actually would have chosen a different caliber for hunting around here, but got a really good deal on a Weatherby last year, and it happened to be in 30-06.

[North Country Gal]

Thanks, Tim. Over the years I have become less and less enamored of trying to "magnum-ize" standard cartridges. I prefer to go right to the appropriate magnum when I need one. The standard 45-70 load, especially, has a long and distinguished record as a hunting cartridge. If I ever really needed a 458 Win mag, I'd go buy one.

[JEBar]

Thanks for the comments.

As I stated above, I have no plans to come close to 40,000 c.u.p., but as I explore the best combination of powder and bullet for my rifle, I want to know the rifle's limitations and stay well under that amount of pressure.

I've loaded and fired way north of 1,000 45-70 dangerous game level loads .... one thing I can say without hesitation is they kick and they kick hard .... I tend to believe that in a single shot the kick might be even harder .... for my use I can't envision the need anything stronger than a top end standard load .... that said, I'm looking forward to learning what you find