The .300 Win. Mag. has a short neck. When it was first introduced, this feature was critisized, and some pundits insisted that all bullets used in it had to be crimped because of this. Nosler even went so far as to produce a special series of partition bullets just for it that had a series of small relief grooves on the shank instead of the one relief groove of the previous bullets (this was in the days when the Nosler Partition was made on automatic screw machines). It has since developed that the .300 Win. Mag. neck works just fine, and no special treatment is really needed. This cartridge's neck is no worse than the .300 Savage or the 7.65X53 Argentine Mauser, for example.

Keep yore powder dry!!