.300 AAC Blackout headstamp list

The recent Oath ammo thread had me wondering about all the .300 Blackout headstamps that have come out in recent years, and as I began looking, I found LOTS of them - some very obscure. It’s a pretty good list for a caliber that has only been around for 4 years for the most part. Some of the below custom headstamps from those manufacturers will exist alongside random commercial brass or reformed 5.56 remanufactured brass which those companies may have initially used.

Here’s the list, and if you have more, please add:

TNQ 300 BLK (Team Never Quit, via Snake River Shooting Products, by PNW)

GORILLA 300 BLK (nickeled & standard brass)

FLA 300 BLK (Florida Arms or Firing Line Arms?)


FC 300 . BLK (Federal) (small dot)

FC 300 ● BLK (Federal) (Large dot)

F . C 300 . BLK (Federal - 2018+) (Two dots)

R - P 300 AAC BLACKOUT brass & nickeled

. R - P . 300 AAC BLACKOUT

. R- P . 300 BLK (late 2018)

*O . A . T . H * 300 BLK Aluminum & brass?

GFL 300 BLK (Fiocchi)

JAG 300 BLK (Jagemann)


SCO 300 BLK (Silencerco)

300 BLK JBA (Jamison / Captech) (fat & thin letters)

norma 300 BLK

SSA 300 BLK (Silver State Armory, by Nosler)


PWS .300 BLK (Precision Weapons Systems)



. Barnes . 300 BLK

NOVESKE 300 BLK (by Nosler)

PNW Arms 300 BLK

GEMTECH 300 BLK (annealed & not annealed) (new type in late 2018)

A P 300AACBLK (Armscor)





HORNADY 300 BLK (fat & skinny letters) (nickeled & standard brass)


SIG 300 BLK (2-dot version 2019 / 2020)

SIG 300 BLK (larger wide-letter format, 2019)

300 BLK ADI (Australian Outback)

ProGrade 300 BLK

. ALEX-A 300 BLK (Alexander Arms)

A-ZOOM 300 AAC (snap cap)

300 BLACKOUT CBC (Magtech) (red or black primer seal)

300 BLK-SUB CBC (Magtech subsonic)

S&B .300 AAC BLK Ö (some subsonics w/ blue primer seal)

>> 300>>BLK>> DANIEL (Daniel Defense)

ATL ARMS 300 BLK (Atlanta Arms & Ammo)

Hornady LNL threaded case

MAI 300 BLK (Modern Arms International)

NEXUS 16 300 BLK (Strategic Armory Corps / Nexus)


WIN 300 BLK (new version 2018)



PPU 300 BLK (Prvi Partizan)

⋆-⋆ 300 BLACKOUT (Starline)

UNDRWD 300 BLK (Underwood Ammo)



APEX 300 BLK . SUB (Discreet Ballistics)

mlm 300 BLK


BLH 300 BLK (Black Hills) (special contract for Dutch Spec Ops).

. X-TREME . 300 BLACKOUT (Freedom Munitions - sold by LAX Ammo after Freedom

⋆ USA ⋆ 300 BLK (Herters via Cabela’s)

GRIND HARD 300BLK (Grind Hard Ammo)

300 BLK CG 18 (Nammo)

300 BLK CG 19 (Nammo)

IVI 300 BLK (General Dynamics Canada)

S3 300 BLK (Shell Shock Technologis)

● 300 ● BLK ● SIERRA

Some manufacturers of .300 BLK that I found who don’t have their own headstamp: - in alphabetical order

American Quality Ammunition

Beck Ammunition (formerly “Right to Bear Ammo”)

Belmont Ammunition (New Zealand)

Big Bear Ammunition

Bite the Bullet

Black Hills … (BHA was using Hornady .300 Whisper brass, so basically .300 BLK, but they labelled it as Whisper)

Black Munitions

Blackwater Precision

Blue River Ammo


Capital Armament (Caparms)

CMMG - (used reformed 5.56 “AAC” brass made by Igman)

Colorado Cartridge Company

Cooper Cartridge Company

Core Ordnance

Crossfire Ammo

Custom Cartridge Inc.

Custom reloads of Dallas

Defensor Ordnance

Denver Bullets

Detroit Ammo co

Discreet Ballistics

Double Tap … (I’m not sure if they have a headstamp or not)

DRT Ammo

Engel Ballistic Research

Fedarm (Knesek Guns)

Flatland Ammo

FOG Ammunition (aka Headwater Ammo)

Fort Daniel

Fort Scott Munitions (aka Velocity Tactics)

Frantec USA

Freedom Munitions

FTW Ammo

G2 Research

Greenline Tactical

Grey Ghost Precision

Gunn Ammunition

Hardened Arms

Heritage Ammunition

Highland Lakes

Hyperion Munitions

ICC Ammo … (debuted a frangible 300 BLK rd at SHOT show 2015 and are using JAG & PNW, but will have their own headstamp coming out in 2016)

Infinity Ammunition

Ironwill Cartridge Company

Kinetic Range by Blok Tactical

LAX Ammo

Liberty Ammunition - (a company rep told me that they plan on having .300 BLK by the end of 2016)


Loon Tactical

Mid America Munitions

Minuteman Munitions

Monolithic Munitions (using R-P brass)

Mustang Munitions

Ozark Ordnance

Neptune Rifleworks

Nexus Ammo

Night Ops

Parabellum Ammo

Palmetto State Munitions (PSA Munitions)

Peak Performance Ammo

Precision One

Rainier Arms

Redline Ballistics

Right to Bear Ammo (now Beck Ammunition)

Scorpion Reloads

SMA Ammo (specialty tracer, incendiary, etc…)


Southern Armament

Southern Ballistic Research (SBR)

Sperry Ballistics

SRA (Steel Ridge Ammo)

Stand 1 Armory

Steadfast (Stillwood)

Surplus Ammo & Arms

Tactical Ammunition

Tennesse Cartridge

TNT Munitions (using reformed 5.56)

Tracking Point Xactshot


Triune Defense

Trophy Ammo

Ultra-Tech Ammo

Underwood Ammo (using JAG, but plans to have their own)

Velocity Tactics (aka Fort Scott Munitions)

Ventura tactical

Victis Munitions

Village Tactical

Wilson Combat … (Using R-P brass)

ZLS Ammo


I also have: AAC 83

I saw that AAC headstamp in my searching, and apparently that is from American Armaments Co (via Igman). and it is converted .223 brass, hence the 83 date. I think there are also some other later dates. It fits nicely as a converted .223 brass though, due to the “AAC” coincidence. There is quite a bit of converted military LC brass, and other 5.56 brass used for .300 BLK, mostly with those remanufacturers who don’t have their own headstamp.

The photo of the AAC 83 headstamp that I have was associated with CMMG Small Arms Manufacturing, POB 369, Fayette, MO 65248.

That’s what I have seen as well Leon. I was under the impression that CMMG had been remanufacturing / resizing huge amounts of Amerc brass, with the idea being that the “AAC” stamp was a handy coincidence for marketing that caliber. There would have been a finite amount of that brass however, so I assume that was a limited production?

Matt, great list, thanks for sharing.

The AAC 83 headstamp in 5.56x45 and 7.62x51 was a made by Igman of Yugoslavia for Nordac Manufacturing Corp. (NMC) in Fredericksburg, Virginia, and the initials stand for “American Armaments Corporation”. This was a deceiving contract intended for El Salvador.



Thanks for the correction Fede. I notice that Ruag / Swiss Munitions is making a .300 Whisper, with a headstamp of T .300 Whisper , but I assume that this is not the same exact spec as the standard 300 BLK?

While I have very few different headstamps in this confusing .300 Whisper, Blackout, 30-221 cartridge, I have a few that I did not find on that list:

JI 30-221
T .300W

I included the “T” round from Thun, Switzerland, because it has only .300W for the caliber designation, not .300 WHISPER.

I don’t know who “JI” is.

I assume that on the LEHIGH headstamp, “BLK-WH” stands for Blackout-Whisper, indicating to me that the two designations are two names for the same cat.

I assume that the “30-221” indicates a .30 caliber cartridge using the .221 case type.

I don’t know why I started this round. While I have a lot of loadings, most all of them are on three or four headstamps. I had no idea there were so many different headstamps and from the list of other makers, potential headstamps.
Quite interesting and discouraging at the same time.

Some of the bullets in (and for) this loading are far more interesting than the cartridge itself. Of course I realize that beauty is in the eye of the beholder.

John beat me to the JI and Lehigh headstamps.

I think that JI = Jamison International.


Summit Ammunition is headstamped SUMMIT 300 BLK.

Thanks for that one - I have only seen what look like reformed 5.56 cases in photos so far.

And thanks John & Paul. Jamison has two different headstamps then it sounds like, and Lehigh has used a mix of JAG, and their own.

Just a quick picture to show 2 variations of Thun manufactured ammunition.


Paul, the headstamp on the left came in boxes by SM and the one at right by Ruag Ammotec AG. There is also a variation of the last without primer crimps and lacquer that came in late SM boxes. Regards, Fede.

Hi Fede,

Yes, you are correct. Here are pictures of a couple of those rounds…




1 Like

For those interested, 5 round sample packs of .300 BLK are available from GEMTECH: gem-tech.com/store/pc/viewca … ategory=32


Paul, great variations, thanks for posting. Are these pressure test cartridges prepared at Thun?

The cases prepared for pressure testing differ somewhat from what I know as standard procedure.
Normally, such a case is first placed in a fixture where a rectangular gap is filed into the rim/base of the case.
This gap corresponds to a stud in another fixture, where the hole is drilled in the case wall.
The pressure barrel also has a stud which ensures alignment of the pressure hole in the case with the pressure gauge in the barrel.

I assume, the straight line visible on the base of the cases shown is used for this alignment instead. This is the first time I see cases prepared for pressure measurements without the gap.

Hi - yes, these are products of Thun. It seems to be standard practice. Here are some other calibers.


As I become more interested in collecting 300BLK headstamps (my first collected rifle caliber… dread), I came across an article from late 2012 by former Hornady employee Steve Johnson. It is a really well-done and thoughtful article with interviews from the most relevant people involved in both the .300 Whisper and .300 AAC Blackout, and explains perfectly why there are different names, and what the differences are. It basically boils down to AAC wanting to have a commercially produced 221-300 cartridge that was SAAMI spec’d, and SAAMI does not accept the use of a cartridge name which was formerly trademarked (like wildcats which may have variations within the caliber). So AAC had to tune up their own load, which is essentially identical to the Whisper, but qualify it through SAAMI because of a military contract involving Remington-manufactured ammo, which also demanded the use of SAAMI specifications:


I just received some Lapua 300blk brass - unloaded 100ct box. These are relatively new in the U.S. market, and photos are basically non-existent on the internet, especially headstamp. There is Lapua’s factory computer-generated image, but nothing real out there, so I figured I should put it here. I think I understand why as to the scarcity of encounters since this brass was $78.00 for 100, which is relatively crazy. Also shown is the very large plastic box that Lapua packs the brass in. The size is apparently due to their trick of putting spaces on the inside of the lid to hold 50 loaded cases.





Here are some others: