matt85
AH legend
i realize the topic of the 45-70 gets brought up a lot but I got in a debate with a coworker earlier today and I felt like posting about it since my coworker made some valid points. his argument was that the 45-70 could produce near identical velocities to the 450/400 3" with the same bullet weight which yielded about the same muzzle energy.
it goes like this:
-45-70 (hot load) = 400gr bullet at 2000 fps, 3553 ft/lb muzzle energy
-450/400 3" (factory load) = 400gr bullet at 2030 fps, 3660 ft/lb muzzle energy
pretty much the same right? at first I couldn't come up with a counter to his argument as it seemed solid at first glance. however, after a little thought and research i found the secret to the effectiveness of the 450/400 3" and why it brings down large animals in a way that the 45-70 cannot match. the simple answer is sectional density! here is a comparison between two bullets:
swift A-frame .458 400gr: SD 0.272 BC 0.258
swift A-frame .410 400gr: SD 0.339 BC 0.367
the 400gr .458" bullet suffers from a serious problem, its short and wide. these are not ideal traits for a bullet you need to penetrate heavy hide, bone, and meat. a proper SD for thick skinned dangerous game has long been considered 0.3+ and for the .458" bullet to reach this it must be at least 450gr. unfortunately the 45-70 is not able to push the 450gr bullet fast enough to achieve the ideal muzzle energy for dangerous game. (according to hornady's ballistic calculator, you would need to push the 450gr bullet at 1900fps to achieve a proper muzzle energy)
i didn't make this thread to argue whether or not the 45-70 was suitable for DG but rather to discuss what at first seemed like it might be a valid argument.
thanks for reading
-Matt
it goes like this:
-45-70 (hot load) = 400gr bullet at 2000 fps, 3553 ft/lb muzzle energy
-450/400 3" (factory load) = 400gr bullet at 2030 fps, 3660 ft/lb muzzle energy
pretty much the same right? at first I couldn't come up with a counter to his argument as it seemed solid at first glance. however, after a little thought and research i found the secret to the effectiveness of the 450/400 3" and why it brings down large animals in a way that the 45-70 cannot match. the simple answer is sectional density! here is a comparison between two bullets:
swift A-frame .458 400gr: SD 0.272 BC 0.258
swift A-frame .410 400gr: SD 0.339 BC 0.367
the 400gr .458" bullet suffers from a serious problem, its short and wide. these are not ideal traits for a bullet you need to penetrate heavy hide, bone, and meat. a proper SD for thick skinned dangerous game has long been considered 0.3+ and for the .458" bullet to reach this it must be at least 450gr. unfortunately the 45-70 is not able to push the 450gr bullet fast enough to achieve the ideal muzzle energy for dangerous game. (according to hornady's ballistic calculator, you would need to push the 450gr bullet at 1900fps to achieve a proper muzzle energy)
i didn't make this thread to argue whether or not the 45-70 was suitable for DG but rather to discuss what at first seemed like it might be a valid argument.
thanks for reading
-Matt