Development History of the .338 Spectre cartridge by Teppo Jutsu
Like the .458 SOCOM, the .338 Spectre cartridge was developed specifically for the AR-15 family of gas-operated, detachable-box magazine-fed firearms. The cartridge is intended to fill the gap between traditional pistol caliber cartridges and existing rifle cartridges used in this weapon system. By offering ballistics similar to the .357 Maximum, the .338 Spectre offers great potential as a single shot, silhouette and small game cartridge. By using .338 caliber bullets, the cartridge offers a nice variety in projectile choice, ranging from 160-grain Barnes X Spitzers, through 180-grain BST to 300-grain HPBT MatchKing rifle bullets. Furthermore, it allows the user to employ existing suppressors for the 9mm without modification, providing enhanced tactical firepower.
The .338 Spectre replaces the earlier designed .358 CQB. The .358 CQB uses the difficult-to-obtain .30 Remington case as a parent case, and head spaces on the case mouth. We felt a more easily obtainable case should be used, and thus the .338 Spectre cartridge is based on the 10mm Magnum case. As before, the case has minimal taper, but now headspaces on the shoulder for improved accuracy. Overall loaded length is similar to the ubiquitous 7.62 x 39 M43 and .223 Remington, and standard .223 caliber AR-15 magazines will accept a limited number of .338 Spectre cartridges. The standard .223 lower receiver for the AR-15 can be used without modification, and the rifle will function in both semi and full automatic modes. In addition to the AR-15 weapons platform, several other types of firearms can be made to accept this cartridge, including the Mini-14, T/C Encore and various bolt and pump action rifles.
(With the advent of the 6.8 x 43 mm SPC, OEM bolts and magazines that will accept the .338 Spectre cartridge are now available, as they share the same rim size. Furthermore, the magazine for the AK-74SU “Krinkov” will accept the .338 Spectre cartridge just fine, and we are working on the first prototype rifle in this cartridge.)
Ballistic performance is comparable to the .357 Herrett or .35 Remington or even the 180-grain load for the .44 Magnum. In the 16" barrel carbine, the .338 Spectre will launch the 180-grain BST at 1950 feet/second, approaching 1520 foot-pounds of energy. By loading the 300-grain bullet at subsonic velocities (980 fps) for suppressed application, the muzzle energy approaches 640 foot-pounds.
For the sportsman, the .338 Spectre offers a user-friendly cartridge in terms of brass forming and reloading, with light recoil and excellent performance on small to medium size game. For the law enforcement and military professional, it offers solid terminal ballistics from one of the most-widely used weapons platforms with minor modification. The wide range of available projectiles should appeal to both the recreational shooter as well as the professional. In the LEA/MIL family, AP, API, and frangibles are available for use in tactical applications.