The 30 Mauser was standardized in 1896, it used relatively high pressure to launch an 86-grain bullet at the astonishing velocity of 1450 fps from the original pistol with a 5½-inch barrel. Along with the 30 Luger, this was among a host of small-caliber pistol cartridges designed around smokeless powder and intended for use in semi-automatic handguns that were all the rage in an era when the revolver was still king. With modern components, when loaded to the significantly higher, current CIP pressure limit of 37,700 psi, the 30 Mauser can launch 93-grain bullets at 1650 fps, using a 5½-inch barrel, making it a formidable self-defense round that generates relatively mild recoil. Use of such modern higher-pressure loads in older pistols is most assuredly not recommended. For those guns, keeping pressure closer to 25,000 psi is prudent. Use of progressively shorter barrels progressively reduces ballistics and does so rather rapidly. As with any bottlenecked pistol round, best practice is to apply a roll-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 crimp the case mouth. Generally, attempting to do both operations in one step is a recipe for damaged and destroyed cases.