Developed to provide maximum performance in a simple, inexpensive blowback pistol, the 9mm Makarov uses a 1-mm shorter version of the 9mm Luger case with the taper removed and loaded with a light bullet at lower pressure. Introduced in 1947, this round gained prominence for a time in the U. S. with the release of Makarov pistols in the civilian market. It uses bullets of about 0.366-inch diameter. The Makarov can generate about two-thirds the muzzle energy of the 9mm Luger. It is considerably more powerful than the 380 ACP due to a larger bore and higher working pressure. As such, it does exactly what the designers intended. While limited in stopping power, it is a good choice compared to other cartridges designed for use in blowback-operated pistols. The downside is, the original pistol was necessarily rather heavy. With such high pressure and bullet momentum, the slide had to be relatively heavy and the gun was constructed chiefly of steel. Compared to modern locking-breach 380 pistols, it is big, bulky, and heavy. Compared to the Makarov, we now have pistols chambered in 45 Automatic that are similar in both size and weight! As with any pistol round headspacing on the case mouth, best practice is to apply a taper-crimp after seating the bullet. This helps to lock the bullet in place against chambering forces that might otherwise drive it into the case. I cannot too-strongly recommend getting a second seating-and-crimping die so you can have one adjusted to only seat the bullet and the second adjusted to only taper-crimp the case mouth. Generally, attempting to do both operations in one step is a recipe for damaged and destroyed cases.