It seems quite common to attribute effectiveness to power generation, or, more specifically to kinetic energy generation. Although they can be related, far too often they are not. A far better measure of effectiveness is tissue destruction. However, even if one wishes to relate effectiveness to power generation, one should keep in mind that there are numerous ways of calculating power. If one prefers to use kinetic energy calculations, one has bought into the view that high velocity is more important than bullet weight or diameter. This may be the case for small or medium game, but the experience of a great many hunters of heavy game clearly places this view in doubt. If one prefers to measure power as the famous African hunter Taylor did, through his Taylor Knockout Values, one finds that a heavily loaded 45-70 generates as big a Taylor Knockout Value at 130-yards as does a 375 Holland & Holland using 300-grain bullets measured at the muzzle. Obviously, this is very different from conclusions drawn based on kinetic energy calculations. However, the major shortcoming of power measurements of any kind is the fact that they do not take bullet performance into account. When one simply adopts criteria that can be observed through simple testing, as opposed to complex theories, it is possible to draw conclusions that are far less likely to lead one astry. Since I am most knowledgeable about the performance of our factory loads, I will compare the performance of our 540-grainer for the 45-70 to factory loads available for the 375 Holland & Holland and the 458 Winchester Magnum, both calibers widely respected for use against heavy game. Interestingly our 540-grainer far outpenetrates anything that can be fired from the 375 Holland & Holland, even including roundnose solids. Yet our 540-grainer is much larger in diameter, and more importantly, sports a meplat (.360-inch), not a gentle roundnose, with a diameter nearly equal to the bore diameter of the 375 Holland & Holland. When we look at the 458 Winchester Magnum, we see a caliber capable of much more power generation than the 45-70, but a caliber that suffers from its inability to use blunt flatnose bullets, unless they are fired from a single shot rifle, something not adviseable when shooting dangerous game. The reason for this shortcoming regards the characteristics of bolt action rifles and the manner in which they move cartridges from the magazine to the chamber. Almost without exception, they will not transit blunt flatnose bullets without hanging up on the rear of the chamber, something that cannot be tollerated when shooting dangerous game. The 45-70 lever-action rifle enjoys the cartridge lifter transit mechanism that allows the use of the bluntest non-expanding flatnose bullets, and this is key to its effectiveness when shooting heavy game. When comparing the properly loaded 45-70 to the 458 Winchester Magnum, we find that as a consequence of the 458s cartridge transit characteristics, one must use roundnose solids if more penetration is required than can be achieve with expanding bullets. This is due, again, to the fact that roundnose solids are easily chambered by a bolt action rifle's mechanism, unlike blunt flatnose bullets. Unfortunately, roundnose solids are notorious for their lack of fast incapacitation, something not disireable when shooting heavy, dangerous game. By comparison, the 45-70 with our 540-grainer is capable of providing far more penetration than the 458 with expanding bullets, with far faster incapacitation than the 458 when it deploys roundnose solids. Given the fact that our 540-grainer will shoot lengthwise through buffalo, with an impressive wound channel diameter, far bigger than that produced by any roundnose solid, can there be any reasonable doubt about its effectiveness on heavy game? None of this results from debateable theory, but from simply testing that any of us can do, and from the field experience of a great many hunters of heavy game, including a great many of our customers.
Best regards, Randy Garrett
http://www.garrettcartridges.com