In 1873, Springfield Armory standardized and introduced the 45-70 Government. The original load was designated as 45-70-405 (45-caliber, 70-grains of blackpowder, and a 405-grain bullet). It was an improvement over the 50-70-450 Government cartridge it had previously adapted to the Model of 1861 muzzle-loading rifle. The 45-caliber cartridge had significantly better ranging potential and was generally considered to be more accurate and, with less recoil, easier for most shooters to learn to shoot well. A load introduced in 1879, the 45-70-500 (45-caliber, 70-grains of blackpowder, and a 500-grain bullet), was a major ballistic improvement, offering almost as much velocity and vastly superior long-range accuracy and delivered energy. This load still holds the record for having the longest range of any cartridge ever standardized by the U. S. Military for use in a battle-rifle! It can do this because the bullet remains stable to terminal range. Loaded with modern propellants and bullets, the 45-70 is entirely adequate for hunting any species worldwide. Many hunters have proven this. A favorite story involves a friend who took his Marlin 45-70 to Africa for a hunt including Cape Buffalo. His guide was a staunch disbeliever in anything lever-action and distained the 45-70 as entirely inadequate. When the time came, our hero at first refused to take the shot because the Cape Buffalo his guide told him to shoot was standing in front of another critter. Our hero refused to shoot for fear of hitting both animals. His guide insisted that he take that shot or pass on his chances for a Cape. When given no good option, our hero took careful aim and fired the shot. He thereby dropped both Cape Buffalos in their tracks. One our hero had to pay for, the other his guide had to pay for. So, if the question is, how effective is the 45-70, the answer is, as effective as it needs to be and more. With lighter modern bullets, it is also entirely adequate for shots to about 200 yards on most big-game species worldwide. I personally wore out the barrel in an 1895 Marlin I bought when I was attending College a lifetime ago. Having shot hundreds of groups with that gun, I know what the modern Marlin 45-70 can do both accuracy and energy wise. About 1995, Bob Behn, then CEO at Marlin, and I had a long conversation about the strength of that rifle. He explained that in the decades since Marlin had reintroduced the 45-70 as chambered in its modified 336 action and using 4140 Chrome Moly steel, they had never seen one destroyed catastrophically by an over-pressure load. They had seen several destroyed by continued use of patently unsafe loads but all of those were battered until headspace was so great the striker would not set off the primer! To do that, every handloader involved had used H4227, which generates such rapid pressure rise that a load generating very high pressure batters the action violently — the force on the bolt accelerates it to sufficient velocity that it peens the bolt against the locking lug and the lug against the receiver. Handloaders using appropriate propellants such as 4198 never destroyed the gun, regardless of pressure. I do not claim the modern 1895 Marlin is indestructible. Of course, anything can be wrecked — I have met the proverbial guy who can destroy an anvil using a rubber mallet. But, with a bit of common sense I can attest that the handloader can easily create 45-70 loads for the new version of the 1895 that will do any job that needs done and be perfectly safe for use in that rifle. As with all cartridges used in guns with a tubular magazine, a properly applied crimp can smooth and ease chambering and a crimp is critical to lock the case mouth into the cannelure and thereby prevent recoil and chambering forces from driving the bullet into the case. In some instances, a roll crimp might be the best option But the Lee Factory Crimp Die usually does a better job and the crimp it applies will not damage a cast bullet as chamber pressure drives that from the case.