Just a dude in BC
AH veteran
Firstly, I know this post is going to cause a fight, so those who are so inclined, grab your popcorn now!
Seems silly to type this, but I keep coming across the threads about hunting DG with a 45-70, and invariably I find the same comment:
“That’s right on the heels of a 458 win mag”
“That’s close enough to a 458 win mag that it makes no difference”
“do a few hundred fps between it and a win mag really make a difference? I don’t think so” “Tones of people have done it in that past!”
Now a caveat: In some cases when you have a solid PH, and when you are experiences, and when you know what you are doing, yea! You can bend the rules a bit, and with proper shot opportunity and placement, take down a buff. But the rest of the time it is not a choice I would call “best practice”. And to try and equate it to a supremely capable round is a bit irresponsible.
Why not? Well it just does not measure up to a 458 win mag in the least little bit. Because of a few factors, the main one being case capacity, the second one being COL, and the third being pressure standard.
Cace capacity first: A 45-70 has around 79-81gr of case capacity, whereas the 458wm has 95gr. That gives the 458wm about a 15-20% advantage right off the hop, depending on brass variation.
Cartridge Overall Length: The max length of a 45-70 is 2.550”, with a case length of 2.105”, The 458 win mag has a COL of 3.340”, and a case length of 2.5”. This means the 458 wm can have .84” of bullet protruding from the case, and the 45-70 can only have .45” of a bullet protruding. So, with equal length bullets, the bullet reduces the usable case capacity of a 45-70 much more than a 458 wm.
Pressure: The 458wm is spec’ed for 62kpsi, and the 45-70 is spec’ed at 32kspi for CIP and less for saami. Though Hodgdon shows data for “modern rifles” at 40kpsi. There is a way to “cheat” this kind of, and that is use a ruger no.1 or equivalent for your 45-70, and then you can safely (only for you) run near 60kpsi. However, 45-70 brass it is not designed to have that pressure run through it. This will cause case head separations quickly and can make the gun unreliable.
However, assuming you can run it at 50kpsi. In a ruger no.1 with a 22” barrel, which is much longer than a standard lever gun. And you want to use a bullet with an SD of at least .3, a good selection would be a 480 woodleigh. Quick Load calculates a max velocity of 1850fps, with the best common powder H335, developing 3660 ft lbs. If you throw that same thing into a 458wm (this time with 60kpsi), it gets 2300 fps with cfe223, and 5600ft-lbs. 50% more energy is not “on the heals of” “close enough” “a few fps different”. That is monstrously different, and to even get that close I had to cheat to give the 45-70 much higher pressure, and a longer barrel than is typical.
You can repeat this in QL to your hearts content, but you can’t get the 45-70 close to a WM. Because the 45-70 case is just too short. You can try and use a shorter bullet to free up case capacity, but if you do that you start lowering your SD. You can switch to mono metal bullets, but then they tend to be long per the same weight, and so sacrifice your case capacity. They will never be close.
This is important to talk about, because the thing we need to keep in mind is that a TON of hunters are in here, who have not hunted Africa, who might not even hunt that much in NA, and they are looking for wisdom within these pages to make the right decision. And: “Hell ya brother, 45-70 lever gun that buff, tons of folks have done it before”, is not the right message.
P.S. Also please consider; a lot of people ask that question because they want to see if a gun they already have (the 45-70) is good enough… By telling them yes, you are robbing them of a reason to go out and buy a new gun… Repugnant…
Seems silly to type this, but I keep coming across the threads about hunting DG with a 45-70, and invariably I find the same comment:
“That’s right on the heels of a 458 win mag”
“That’s close enough to a 458 win mag that it makes no difference”
“do a few hundred fps between it and a win mag really make a difference? I don’t think so” “Tones of people have done it in that past!”
Now a caveat: In some cases when you have a solid PH, and when you are experiences, and when you know what you are doing, yea! You can bend the rules a bit, and with proper shot opportunity and placement, take down a buff. But the rest of the time it is not a choice I would call “best practice”. And to try and equate it to a supremely capable round is a bit irresponsible.
Why not? Well it just does not measure up to a 458 win mag in the least little bit. Because of a few factors, the main one being case capacity, the second one being COL, and the third being pressure standard.
Cace capacity first: A 45-70 has around 79-81gr of case capacity, whereas the 458wm has 95gr. That gives the 458wm about a 15-20% advantage right off the hop, depending on brass variation.
Cartridge Overall Length: The max length of a 45-70 is 2.550”, with a case length of 2.105”, The 458 win mag has a COL of 3.340”, and a case length of 2.5”. This means the 458 wm can have .84” of bullet protruding from the case, and the 45-70 can only have .45” of a bullet protruding. So, with equal length bullets, the bullet reduces the usable case capacity of a 45-70 much more than a 458 wm.
Pressure: The 458wm is spec’ed for 62kpsi, and the 45-70 is spec’ed at 32kspi for CIP and less for saami. Though Hodgdon shows data for “modern rifles” at 40kpsi. There is a way to “cheat” this kind of, and that is use a ruger no.1 or equivalent for your 45-70, and then you can safely (only for you) run near 60kpsi. However, 45-70 brass it is not designed to have that pressure run through it. This will cause case head separations quickly and can make the gun unreliable.
However, assuming you can run it at 50kpsi. In a ruger no.1 with a 22” barrel, which is much longer than a standard lever gun. And you want to use a bullet with an SD of at least .3, a good selection would be a 480 woodleigh. Quick Load calculates a max velocity of 1850fps, with the best common powder H335, developing 3660 ft lbs. If you throw that same thing into a 458wm (this time with 60kpsi), it gets 2300 fps with cfe223, and 5600ft-lbs. 50% more energy is not “on the heals of” “close enough” “a few fps different”. That is monstrously different, and to even get that close I had to cheat to give the 45-70 much higher pressure, and a longer barrel than is typical.
You can repeat this in QL to your hearts content, but you can’t get the 45-70 close to a WM. Because the 45-70 case is just too short. You can try and use a shorter bullet to free up case capacity, but if you do that you start lowering your SD. You can switch to mono metal bullets, but then they tend to be long per the same weight, and so sacrifice your case capacity. They will never be close.
This is important to talk about, because the thing we need to keep in mind is that a TON of hunters are in here, who have not hunted Africa, who might not even hunt that much in NA, and they are looking for wisdom within these pages to make the right decision. And: “Hell ya brother, 45-70 lever gun that buff, tons of folks have done it before”, is not the right message.
P.S. Also please consider; a lot of people ask that question because they want to see if a gun they already have (the 45-70) is good enough… By telling them yes, you are robbing them of a reason to go out and buy a new gun… Repugnant…
