.300 AAC Blackout headstamp list


Here is a better quality image of a Master Arms International headstamped case (unprimed) that I recently received:



[quote=“DKConfiguration”]A company by the name of Modern Arms International of Phoenix, AZ is getting their own headstamp in .300BLK and will soon offer a 240gr subsonic load for retail sale. They also have several interesting looking AP loads in various calibers (for agency sale only).



Beat me to it dangit!

I talked to Jeff the other day, part owner of MAI. Very cool guy. I have a 100 pack of their 240 grain sub load in blackout & a 100 pack of their 7.62x51 187 grain subsonic coming to test. Very excited, this is good looking stuff! Jeff seemed very knowledgeable & has a neat history behind this company.



I noticed today that Atlanta Arms & Ammo now has their own headstamp in .300 Blackout, which figures since they have invested in headstamps for most calibers these days. I believe this is the most recent .300 BLK headstamp out.



Winchester is finally on the .300 Blackout bandwagon:



Dated AAC headstamp,(19)83 ? Cartridge produced using modified AAC (American Armaments
Corp) /Igman 5.56x45mm cartridge case? Courtesy of Forum member “xjda68” (Joe):

Can anyone provide information on this cartridge?



Further up in this thread Fede explains that these headstamps in 5.56x45 and 7.62x51 were 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.

In recent years these 5.56 cases were popular to reform and load for .300BLK because of the coincidental “AAC” lettering (.300 AAC Blackout). I don’t know who exactly loaded them, and there are likely a few small manufacturers and/or individuals who did.



Well I missed that big time! The story behind the AAC/Igman 5.56x45 round is covered by Fuchs in his 5.56 ebook (2012).

At least there is now a picture posted of the headstamp.




Gunn Ammunition also makes the .300 BLK but does not have their own headstamp.


Just received some recent production Underwood Ammo .300 BLK loaded with the Lehigh Controlled Chaos 115gr projectiles, and they have their own headstamp now:


I received a box of the Winchester “Deer Season” ammo today (box shown earlier in thread). Here is the headstamp:


I received a box of the Nexus brand .300 Blackout ammo from Strategic Armory Corps recently. Dated headstamp and box below:


So was choosing .300 Whisper/Blackout a good or bad choice for me to begin cartridge collecting? (Joking, joking)


I noticed on the Prime website last week that they have .300 Blackout listed and ordered a box. Still made by RUAG as the back of box indicates, and has a surprising amount of ballistics data on the back as well. It is an unconventional 30-pack, which unsurprisingly jumbled and jostled inside the box that partly popped open in shipping.


I’m curious if there are any military style 300 BLK headstamps (other than the AAC 83), or examples with no headstamp having a military provenance?


Do not put too much trust in the ballistic data.
One thing is the computed data printed on the box. This may be quite different from what you experience on the range. Getting drag coefficients right at transonic/subsonic speeds is extremely difficult, due to the very small changes of force involved at these low speeds.


The only military style headstamps I know of are the Thun ones, which are technically done as .300 Whisper. Nexus styles their headstamp as military with the date, but it is for retail sale. That AAC 83 one is just reformed 5.56 brass which was popularly resized to .300blk due to the coincidental AAC reference matching the full caliber name prefix.


True about the data. There are extremely few shooters in the U.S. who would be able to make any sense or use from that data, and I am sure Prime put it on the box just to give the feel and look of a higher-grade match type ammo.


I just noticed on Aguila’s website that they list the .300 Blackout as one of the 6 rifle calibers they are producing. We should see it soon I hope, and with an Aguila headstamp I presume.



Matt, thanks a lot for the numerous updates. You can also add SAKO to the list (announced in late 2015). Headstamp is SAKO 300 BLK.