Introduced in 1964, the 444 was Marlin’s first effort toward reintroducing big-bore lever-action chamberings that had been absent since about 1935 in both the Marlin and Winchester lines. With introduction of the 444, Marlin converted all production of all centerfire models from 8620 Carbon steel to 4140 Chrome-Moly steel that has significantly higher strength and much greater fatigue resistance. As such, Marlins built after about 1964 are much stronger and more durable than earlier guns. Gun-writers of the day introduced much confusion when they claimed only the 444 used the superior steel. This can be traced to one writer who guessed, wrongly, and those who read his erroneous statement and then parroted it. In any case, the 444 Marlin is an extremely strong gun. When Winchester adopted the 444 chambering in its 1894, it felt the need to thicken the receiver sidewalls. Marlin had to make no changes other than to use better steel and even that was unnecessary, with proper heat-treating 8620 would have sufficed but out of an abundance of caution and looking forward to chambering with even more powerful cartridges, Marlin made the change to 4140. They did this for all centerfire models because that avoided any possible confusion on the assembly lines; having receivers made from two types of steel is a recipe for uncertainty and the problems that will engender. Original 444 loads used the same bullet as the 44 Magnum but loaded to generate as much energy as typical factory 30-06 loads. Soon, Remington added a superior 265-grain load with a bullet designed to expand properly at the velocity the 444 would generate. For entirely mysterious reasons, factory loads were soon downgraded about 100 fps. With modern components, handloaders can easily exceed original-load performance without exceeding the 44,000 CUP SAAMI pressure limit. As with the 44 Magnum Marlin, many handloaders immediately set about badmouthing Marlin for adopting a relatively slow rifling twist. In contradiction to so much noise to the contrary, Marlin made no mistake, it spent considerable time and money figuring out the most accurate rifling twist rate for the 444 when launching bullets weighing up to about 300-grains, which it figured would be the heaviest anyone would want to use. As such, original 444s are extremely accurate guns, just as the original 44 Magnum Marlins are. If accuracy matters to you, get one of these early 38-twist guns. If you simply must shoot bullets heavier than about 300 grains, get a Marlin 1895, 45-70! 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.