Designated Marksman Rifle in .338 Spectre.

MagPul PRS stock, LaRue scope mount, Leupold scope, Daniel Defense receiver and hand guard and a nice suppressor to round it out.  Whatever he's hunting, it doesn't stand a chance!




New Video of 300gr .338 Spectre

The new .338 Spectre in various guises shown flanked by the 5.56x45 (left) and 7.62x39 (right). Left to right - 160 gr Barnes X, 200 gr Ballistic Silvertip (both "natural" and "tactical black") and the Sierra 300 gr HPBT MatchKing for subsonic applications requiring minimal signature.

CQB: Barnes 160 gr X Spitzer, 16" barrel, 1,800-2,000 fps 
Small Game: Comb. Tech. 200 gr BT, 20" barrel, 1,600-1,700 fps 
Minimal Signature: Sierra 300 gr HPBT MK, 1,000 fps 
(the latter employs standard 9mm suppressors to ensure a truly minimal 
signature for the discerning professional) 

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.  It shares rim size with the new Remington 6.8 x 43mm SPC cartridge, allowing use of OEM bolts in this caliber.


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.

Custom AR-15 SBR in .338 Spectre using PRI 6.8 x 43  magazine, 

Ameetec side-charging upper receiver and custom installed Carbon-15 hand guard and rail.

Shown with 200-gr BST rounds and Walther P22 with Gemtech Outback II.

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 Starline 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

click to see larger image

Standard .223-caliber AR-15 magazines will accept a limited number of .338 Spectre cartridges, whereas the 7.62x39 magazines are fully compatible.  Due to the fact that the cartridge shares rim and head dimensions with the new 6.8 x 43 SPC, the preferred magazines are those made specifically for the 6.8 x 43 by PRI.  Tthe 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.

AR-15 carbine in .338 Spectre using hybrid 7.62 x 39 magazine, 

Mangonel flip-up sights and AK-type muzzle brake.

Ballistic performance is comparable to the .357 Herrett, .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 BT at 1,800 ft./sec., approaching 1,300 ft-lbs. of energy. By loading the 300-grain Sierra HPBT MatchKing bullet at subsonic velocities (1,040 ft/sec.) for suppressed applications, the muzzle energy measures 720 ft-lbs., surpassing both the high velocity 115-grain load for the 9mm Parabellum as well as the 240-grain .300 Whisper load.



A .338 Spectre ultra short (8.5") PDW built by ADCO Firearms using one of our barrels.  Click the link below for footage of this PDW version firing 300 SMK subsonic loads with a Yankee Hill Machine "Wraith" 9mm suppressor.  

.338 Spectre PDW Full Auto Footage
Click here to view video footage


Factory loaded ammunition for the .338 Spectre may be bought from Reeds Ammunition and Research.  Ron has done some extensive loading and testing of the .338 Spectre using the upper shown above and is offering a variety of loads.  Both accuracy and terminal ballistics have proven to be outstanding and the table below summarizes his testing and development:

Bullet Maker  Weight Style Velocity  Penetration Tumbling Expansion
(Brand) (grain) (type) (fps) (in. of gel) (after in.) (in.)
Barnes 160 X Spitzer 1750 Unknown No No
Hawk 180 Soft Point 1500 16+ No 0.9-1.0
Nosler 200 Ballistic Tip 1240 20 10 minor
Speer 200 Soft Point 1240 22 No No
Hornady 200 Soft Point 1500 24+ Unknown Yes
"cast" 200 LFN ? 16+ No 0.5-0.6
Hornady 225 Soft Point 1460 24+ No Yes
Hornady 225 SST ? ? ? ?
Nosler 250 Partition 1040 24+ 6-8 No
Sierra 250 Match King 1040 24+ 7-8 No
Sierra 300 Match King 1040 24+ 3-5 No
REED 250 Frangible TBD TBD TBD TBD


In addition, Southern Ballistic Research carries factory loaded .338 Spectre ammunition AND brass with proper headstamp.




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 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. Reloading dies for the .338 Spectre can be obtained from CH Tool and Die ( as well as the Hornady Custom Shop.



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Copyright 2011 Teppo Jutsu LLC.
Last modified: June 1, 2011