Check this out. All this time I thought there was only the .50 Beowulf but apparently I was wrong.
All these calibers have a common thread that their design is meant for use in the AR platform, meaning they will fit an AR magwell and in some cases an AR mag.
The disadvantage that is common to most all of these, and which is what is going to keep them in "wildcat" country, is the "proprietary" desire by the manufacturers to keep the caliber in their brand of AR platform. One can argue that this is a good thing from a Quality Control viewpoint, but one can also argue that this is a bad thing from a home loader viewpoint. A cartridge simply can't become popular if it is in such a limited offering that you can't even find reloading dies!!!!
.458 SOCOM: Built by Teppo-Jutsu
.50 Beowulf: built by Alexander Arms
.499 LWR: built by Leitner-Wise Rifle Company
The .499 is like a "magnum" version of the .50 Beowulf... if the Beo is a .38, the .499 LWR is the .357 magnum. They might actually have been designed by the same team that eventually broke up and went separate ways, but it is hard to figure out the truth vs. the FUD. The .499 is a .50. It is .499 because of the potential for .50 cal bans.
Leitner-Wise Defense, Inc.
Defense Review - Alexander Arms .50 Beowulf: One Serious .499 Caliber Tactical Carbine.
More Punch for the AR
12,5mm (.499) battle rifle LW15.499 [Archive] - Military Photos
.500 Phantom: subsonic .50 based on the .458 in a larger caliber, and for the AR-10 platform.
.450 Bushmaster "Thumper": Think .50 Beowulf in .450, supported by both Bushmaster and Hornady. This is a "publicly supported" caliber that both companies are openly promoting to the commercial market. No word yet on reamers.
The Teppo Jutsu range of cartridges
More Punch for the AR
Feisty Rooster's 500 PHANTOM Page
Welcome to CH Tool & Die / 4D Custom Die >> reloading dies and brass, among other things
7.62x51mm, 6.8, 5.56 Ammunition Custom Brass Cases >> .499 LWR brass
Hornady Manufacturing, Inc.
Left-right: .223, .458 SOCOM, .50 Beowulf, .499 LWR:
Does anyone have information about other .45/.50 intermediate cartridges? Please share!