The Black Hills Gold .243 Winchester loads an 80-grain Hornady GMX bullet at 3200 feet per second, generating 1819 foot-pounds of muzzle energy. The GMX (Gilding Metal eXpanding) is Hornady's original lead-free hunting bullet—a monolithic copper-alloy design that preceded the CX. Black Hills' precision loading brings match-grade consistency to this lead-free option, making it suitable for accuracy-conscious hunters in non-toxic ammunition zones.

The GMX bullet expands into petals while retaining virtually all its original weight. The grooved shank reduces pressure and fouling, addressing the common complaints about copper bullets. The G1 BC of 0.273 is typical for 80-grain copper bullets—adequate for hunting distances but not optimized for extreme range. Black Hills' attention to loading consistency means this ammunition shoots tighter groups than most factory copper loads.

This ammunition serves hunters who need lead-free performance with Black Hills accuracy. California deer hunters will appreciate factory ammunition that actually shoots well, rather than the inconsistent groups some budget copper loads produce. The 80-grain weight handles deer cleanly at moderate distances, and the full weight retention ensures penetration on quartering shots. Hunters who reload can use the brass to develop their own GMX or CX loads.