Introduced in 2019, the 350 Legend is nothing more than a slightly shortened straight-walled version of the case used for the 223 Rem. It was developed to provide maximum AR-15 platform energy with a straight-walled case that would be legal for hunting where use of such a case design is required by law. With the widespread use of the handy AR-15 platform, the 350 Legend has a chance of becoming relatively popular. Time will tell. Loaded to 55,000 psi and with an overall length up to 2.26-inches, energy and trajectory are similar to standard factory 30-30 loads. Obviously, when loaded with the right bullet, the 350 Legend will do anything the 30-30 has been doing so well for so long, although it will not be as useful for most shooters when attempting shots beyond about 100 yards. As with any round headspacing on the case mouth, best practice with the 350 Legend 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 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. Heritage of this case dates to 1873 with the introduction of the 32-20 WCF.