A Brief History of the .375 Reaper

UPDATE 2016 : A number of people claiming to be customers of Whiskey 3 Precision Systems (which may be going by the name Terminal Ballistics Group today) have complained to TFB regarding their orders not being fulfilled. We recommend caution when placing orders. 

I have written a couple articles now on the .375 Reaper round in development.  If you want to look back at those, you can find them here and here.  This afternoon I spoke to John Culpepper of Whisky 3 Precision Systems about the .375 Reaper round that they are currently developing.  As I suspected the round was motivated by the shortcomings of the .300BLK round and the extreme cost of the .458 SOCOM.  The .375 Reaper gives the shooter a lot more energy on target and also better accuracy out to 300yds over the .300BLK, but also costs far less to buy complete rounds.  Even more cost effective is reloading your own rounds with easily obtained, readily available components.

375 Reaper blackout comparision

Speaking with John he is very passionate about the round he is creating.  They have designed and made entirely new BCG’s to handle the round from scratch.  The BCG’s for the .375 Reaper are still a MIL-SPEC and will work in any AR, but they are strengthened to handle the larger round and have longer lugs on the bolt.

Personally, after seeing their real world ballistic tests I am impressed with the round for short range applications.  It hits much harder than the .300blk and can be made in both a sub-sonic and standard velocity round.   The other nice thing about the .375 Reaper is that all the components are readily available at your local shop and brass can be had from just about anywhere you can find .308 casings.

Take a read below at the release from Whisky 3 Precision on the history and thought process behind the round.  While I have never really been a big fan of all the crazy wildcat loads guys are working on stuffing into the AR15 platform, I do think that these guys are onto something and are making an exceptional  new round.

The New Kid on the Block with a Big Bore Bite!!   The Bacon Busting .375 Reaper   Cartridge.


Whiskey 3 Precision Systems LLC is one of those new companies that has sprung up in response to solving problems in the firearms industry with disappointments or complaints with certain cartridges and first and foremost producing some of the industry’s  most accurate, high ballistic coefficient,  explosively devastating and deep penetrating projectiles on the planet with their Alco TAC-PM ™  projectiles.  As a result of getting the best they could squeeze out of their projectiles was born the newest AR15 and Bolt Action  weapon platform, the .375 Reaper .

The concept and birth of the .375 Reaper Cartridge was brought forth by its designer John Culpepper “U.S. Army Ret” in an effort to improve over the 300 blackout and the .458 SOCOM due to many industry complaints of either not enough kinetic energy and range or not enough range and inaccuracy and lessened magazine capacity and cost effectiveness of the platform.

The idea was to keep the design simple, affordable and ease of versatility / compatibility with the lighter AR15 platform to save on weight with the highest attention to detail during development…..on into production, as well as using a common parent case design (.308 or 7.62×51) and utilize commonly found .375 caliber projectiles or high ballistic coefficient projectiles to obtain the best range and accuracy.  The Parent .308 or 7.62×51 case is cut down, resized and the case shoulder is formed just as the 300 Blackout round is made from the 5.56 case, trimmed and ready for reloading.  Magazine capacity for the .375 Reaper is at 15 rounds stagger stacked in the standard  G.I. 5.56 magazine and you can also use the 6.8 SPC magazines or replace your AR15 5.56 magazine follower out for a 6.8 SPC follower to assist in better feeding of the cartridge. The Reaper uses an improved Proprietary bolt which was  a collaboration with Whiskey 3 Precision Systems and Young Manufacturing,  that is much stronger than the .458 SOCOM and 7.62×39 bolts that most find on the market. They built this bolt from the ground up and added the strength on the bolt face that was causing bolt failures/ sheared bolt lugs in a lot of larger caliber AR15 platforms.

All that is essentially needed to convert your current platform over to the Reaper is the Proprietary bolt swap and a barrel that they produce as well.  As a rule of thumb for this they kept it very simple and it worked!

The Real world numbers that they are getting out of this tiny cartridge are quite impressive indeed.  Pushing 195 and 200 grain projectiles 2478 fps out of a 16inch barrel is moving for a lightweight platform.  They are also pushing 250 grain bullets over 2000 fps which is quite the feat.  You can also run this platform suppressed and hey have demonstrated this on a video that surfaced in the Firearms Blog Online from You Tube the link to the article can be found here.

Update on .375 Reaper from Whiskey 3 Precision Systems

For all the Extreme Hog Hunters out there that want more knock down and range over the 300 AAC Blackout and affordability as well as extended range and accuracy over the .458 SOCOM, the .375 Reaper  can easily assist you in taking some porker souls and put some bacon on the table!!

If you are looking for a round that has more kinetic energy and range over the 300 blackout or if you want more magazine capacity, superior accuracy and cost effectiveness over the .458 SOCOM than look no further, the .375 Reaper is here and ready to get hog nasty with anything you want to throw his way!

Manufacturers Information:

Please contact W3PS using the contact form to get in touch with them for licensing inquiries.




  • John Allen Culpepper

    Again Sam, you are the man…….!!! Keep up the great work and Thank You for your interest in this cartridge!!

  • sianmink

    Sounds like they’re mostly replicating the Russian 9×39 cartridge, which isn’t entirely a bad thing. they’ve doubled the velocity of the Russian round, too. What’s the weight of the subsonic round going to be? 300 grains? More??

    • John Allen Culpepper

      Anything really 280 grains and up to 400 grain can be used for sub sonic work. I have tested up to 375 grain so far and the most common is the Barnes TSX 350 grain

      • iksnilol

        That’s what I was thinking. It is essentially a 9x39mm with a longer case. How does it compare to .510 Whisper?

        Seems cool, though I might as well use 9×39 since I can easily get x39 cases.

        • John Allen Culpepper

          .510 whisper is designated as only a sub sonic cartridge in reality. The difference would be the .375 Reaper ™ is versatile as you can use it either super or sub sonic and get big bore energy levels out of it on a small platform.

          • iksnilol

            Stupid question I will admit: Can the .375 Reaper do 2000 joules at 100 meters in subsonic format?

            In Norway things are only legal for moose if they do 2000 joules at 100 meters and I am a bit intereseted in a subsonic cartridge and this seems way cheaper than .510 Whisper (.308 brass vs .338 Lapuab brass).

          • John Allen Culpepper

            That’s not gonna happen sub sonic for this cartridge unfortunately. ….the closest we can get with a 400 grain projectile in a Bolt action gun sub sonic is 1045 joules at 100 yards. Now super sonic running a 235 grain projectile at 100 yards is 2312 joules.
            And even more than that with the lighter weight projectiles because the velocity jumps up tremendously.

      • sianmink

        Yow that sounds like it could really put the hurt on hogs or goblins. Thanks!

  • John Bear Ross

    Mr. Culpepper,
    Are we limited to 16″ for the barrel?
    Are there any velocity gains for 18″, 20″, or 20″+ barrels?
    I’m a big boy, and want to max the supersonic side of the cartridge.


    • John Allen Culpepper

      There are advantages of the longer barrel lengths. ….and yes we are going to offer them in 18 inch and 20 for the AR 15 platform and up to 20 ,22 and 24 for the bolt action platform.

  • Dracon1201

    Mr.Culpepper, is this going to be effective in an SBR? As in, short barrel lengths like a .300BLK?

    • John Allen Culpepper

      Yes it is….same almost identical effects but with a complete powder burn at 10.5 and 12.5 inches of barrel as opposed to 9 inches in 300 aac due to their being more powder to burn in this .375 Reaper ™ case.

  • Steve Truffer

    What, its not rocket propelled, or sprinkled with fairy dust? Boring.
    This is awesome. Now, with the AK natively using cartridges of this size, I’d love to see barrels chambered in this hog buster for my favorite action.

    • John Allen Culpepper

      It could become a reality soon…..stay tuned. Lol

      • Steve Truffer

        mmm. I forsee the domestic Vintorez project going places with this…

        • John Allen Culpepper

          Email me some info on getting what you have in mind going and….of course if you can gain any traction with guys interested in it let me know. Email me direct at whiskey3precisionsystems@gmail.com

          • Steve Truffer

            A beefy, subsonic, high BC pill in an AK package. There is a group at http://vssvintorez.tumblr.com/ working on a domestic VSS under the codename “Yedinorog”. This cartridge, with their rifle, would be one hell of a package.
            I sent them some encouragement.

          • John Allen Culpepper

            Roger that….I agree! Send the boys over there my way with any questions.

  • Are there any other “new” calibers/cartridges in development? I’d love to know.

    • John Allen Culpepper

      With us yes….all Reaper ™ cartridges. 6mm, 6.5mm, 7mm, .257, .30 caliber, 338, 358, 408, and 416 Reaper ™. All based on the 308 Winchester case that can be converted by the end user in their garage like 300 blackout with the proper die set. All using pistol powders as well. Our Facebook page has a few of those cartridges in some pictures next to a full length .308 Winchester for comparison. Pretty wicked looking.

  • Matrix3692

    I wonder …… has anyone tried an aluminium core bullet? Maybe a 50 gr bullet? i wonder what kind of performance would it yield?

  • Beaumont

    Looking forward to more news about this round. It seems to be a useful, versatile round. Even if it wasn’t, those “crazy wildcat loads” are still fun to play with.

  • Anybody else raising an eyebrow high at the idea that this cartridge will provide “more range” with its short stubby case and short bullet ogive than cartridges that already exist for the AR-15?

    • John Allen Culpepper

      Nope……input it into a ballistics calculator and let me know what it says. Real world figures prove this too…..this isn’t the .458 socom style projectiles being shot here.
      .375 caliber projectiles in general have very good B.C’s and this holds true in this caliber as well

  • wvhillbillie

    So is the barrel extension proprietary as well?

    • John Allen Culpepper

      No hillbillie….I’ve already told you guys this…….it’s not and its nothing special.

      • wvhillbillie

        Understand I have not been trying to give you a hard time. I’m interested in this round and have been looking for actual facts. My question is in response to the article it states the bolt has longer lugs.

        • John Allen Culpepper

          I understand to a point. …but after a while of repeating myself I hope you can understand that to a degree as well. All I can say is I had a solution to some of the problem that has been facing the industry and the bolts that have been around. In response to that employed and collaborated with an Aerospace engineer…Ie: Young Manufacturing Inc one of the the best in the business to help us with this and we maxed it out where it was weak to include using some quality steel. What can I say man……it wasn’t that hard. Folks make things way harder than they need to be sometimes. It works and we are happy. Demos are being done nationwide for the cartridge now and video is up of the gun running with the photos of the primers to boot. Pressure tests are being done in the coming weeks as well just for the skeptics but the round is standing pretty tall on his own two feet as I promised it would. I’m not in the business of smoke and mirrors. This industry is too small for that……I have a family to take care of and I have to sleep at night. If you really have any questions or wanna chat just call me anytime….or email me direct at whiskey3precisionsystems@gmail.com