.585 in (14.9 mm)
| Rebated rim, bottlenecked|
The .585 Gehringer is a wildcat elephant gun cartridge based on the .585 Nyati. The cartridge retains the .585" bullet diameter but the case has been lengthened and the rim diameter reduced to fit bolt faces designed for cartridges similar to the .416 Rigby. It was designed over several years by Karl Gehringer, member of the Australian wrestling team, during service in the Australian Armed Forces.
3.25" Bertram brass can be used as a basis for .585 Gehringer cases. Cases need to be trimmed to 3.06" length and the rims rebated to fit a .416 Rigby bolt face. Case capacity is 200 grains to case mouth.
.585 Gehringer Wikipedia
Like most elephant gun cartridges the purpose was stopping power on large dangerous game at close quarters. Power is dependent on the practicalities of gun weight and recoil. Like most 3"+ .585" wildcats, the .585 Gehringer will exceed 2,600 ft/s (790 m/s) with a 750gn bullet for near 11,400 ft·lbf (15,500 J) muzzle energy (roughly 4 times the power of 7.62×51mm NATO).
In 2001, Woodleigh 750gn softpoint and FMJ bullets were tested to 2,350 ft/s (720 m/s) as a suitable hunting load. Geoff McDonald of Woodleigh also provided a special run of 900gn softpoints for the rifle.
The test rifle was a CZ-550 in .416 Rigby fitted with a 25" .577 Tobler barrel of 1:22 twist rate chambered with a 2.8" Nyati reamer.