.300 AAC Blackout headstamp list


I just received another box of S&B .300 BLK ammo, and I notice that while the cartridges are exactly the same, the box has changed quite a bit since the first one I received from when these first showed up in the U.S. back around Dec 2015 / Jan 2016. I can only guess that this new box style with the lion near the CIP logo is around 1-year newer than the first box I had. The bottom and back of box are the same, but the sides, top and front are all different. Other than the lion logo, I notice that they are using a more standardized “S” for “Sellier”, whereas their stylized cursive version from before reads more like a “L” to buyers not familiar with the brand, and who thought they might be “Lellier & Bellot”. The newer one is shown as the top box in the below comparison images:


It looks further “Americanized” with the “8.0” instead of the European style “8,0”


Here is another one. Jan




I received a box of Rainier Arms .300BLK today. Another good-looking new BLK headstamp:



I just became aware that Discreet Ballistics in Plainfield, New Hampshire has a custom headstamp, done by JAG on their .300BLK cases. They do two basic load types, but tailor them based on barrel length, which is a match-tailored option that you normally never find from retail ammo.

The heasdtamp is: APEX 300 BLK - SUB

A blurry shot from his Facebook page shown here, I should have a better image scan next week.



Here is a better scan of that Discreet Ballistics headstamp. I’m not actually sure why he uses the word “Apex”, other than the implied notion of being a premium load, which they all are from Discreet. The Apex brass is made by JAG. His solid copper expander is a custom 188gr projectile from Peregrine Bullets in South Africa, and as far as I know, he is the first manufacturer in the U.S. to be loading any of their projectiles. That subsonic SCHP load is all on Lapua brass.



A few months ago I built myself an AR in 300 BLK and I’ve been taking a lot of notice of all the different ammo available. Thought I found a new one today, but the H/S is already listed. I thought the packaging might be interesting. It’s actually ADI from Australia, not Outback.


From an undisclosed highway rest stop somewhere in eastern Ohio, on my way to SLICS… came across two new .300 BLK items at Cabelas yesterday. One is yet another style of S&B box, but the headstamp is the same, and the other was a new style of Remington box which did have a new headstamp. The first headstamp variation from Remington in this caliber since they made the first Blackout headstamp 7 years ago. Hard to get a good image with the phone on the road, but the two dots and the abbreviated nature of the RP headstamp are evident


Here is a better image of the newly found Remington headstamp from a fresh box at Cabelas last week (top left). The index number on that new Remington box is L300AAC4 by the way. I also show the two other known Remington headstamps (nickeled and standard brass) on the bottom of the photo. While at SLICS, Zac Weighman wandered over and kindly handed me what I at first thought was one of the same familiar R-P headstamps which originated back in 2010, but turns out to be a new version with the two dots (top right), and appears to be from at least a few years ago. So there were two early version of the R-P headstamp with at least one coming in a nickeled version, and now this new one.



I was excited to find at SLICS a new European .300 Blackout headstamp from SAX Munitions of Germany. I am not certain what the “mlm” stands for, and I also can’t find anything on .300 Blackout at the SAX website or catalog, but here it is with a custom solid copper expanding projectile of some sort:



I don’t know what other SAX headstamps look like, but this one has a sort of rough home-made look to it. That might be because this is a preliminary run, or experimental - not sure.



it incredible the number of headstamp for this “new” round

i just would know if norma or lapua offer loaded rounds ?


Matt, this cartridge was loaded with a Sax 126 gr KGG projectile by Karl-Heinz Müller Munitionshandel (trademark m|m). They used to load cartridges using the .300 Whisper designation as well.




Matt, I forgot to add that the case was manufactured by Süddeutsche Hülsenmanufaktur.


Interesting - thanks!




I found a Black Hills .300 Blackout with headstamp “BLH 300 BLK”.


Neat, that would be a brand new thing I guess? Hadn’t seen that before.


Over the weekend I received some recent production Federal and Barnes .300 Blackout, and there were new headstamp variations for both. Dots and spacing are the difference for them. I presume Federal is making their own brass as usual, but with Barnes - who knows, could be Remington, JAG, or almost anybody these days. To me, the new Barnes headstamp has a Hornady look about it.


Just found a new Winchester headstamp for Blackout. This 2018 version showed up in Winchester’s new white box 125gr open-tip stuff for this caliber, index number: USA300BLK. The previous, and only other Winchester headstamp had the word “Winchester” spelled out entirely.


Also shown is what S&B is doing with their subsonic .300BLK lately - sealing the primer with bright blue sealant:



Without the boxes on the shelf in front of you it’s hard to know if a certain box of ammo has a new headstamp yet, and this Ammo Inc .300BLK box is my 3rd or 4th try at getting their very recent production new headstamp in .300BLK. Finally got one! (before they were all HPR headstamps)