Many of you may have read the title and asked: “What in the world is a .277 Wolverine?”. So first, let’s see what cartridge it is. In a nutshell, it is a wildcat cartridge based on .223 Rem or 5.56 NATO case with a .277 caliber (6.8mm) projectile. It is developed by Mad Dog Weapon Systems.

L-R: .223 Remington, .277 Wolverine, .300 Blackout, 6.8 SPC

The .223 Rem shoulder is moved back and the case length is shortened. The overall length of .277 Wolverine (.277WLV) is 2.26″, which makes it possible to fit into AR-15 magazines. Just like the .300 Blackout, it only requires a barrel change to build an AR-15 rifle chambered in this caliber. In fact, this cartridge comes pretty close to the 6.8 SPC but lacks the disadvantages associated with the latter (need of a different/optimized magazine and different bolt, reduced magazine capacity etc.). Particularly, the .277 Wolverine pushes a 90 gr, 100 gr and 110 gr projectiles at 2700 fps, 2600 fps and 2500 fps respectively (from a 16″ barrel). There you have a brief description of the cartridge. For more information visit MDWS’s website.

As the title of this post implies, the designer of this cartridge has released it to the public (effective of April 18, 2017). It means that this cartridge is no more a proprietary one and anybody willing to manufacture it can do it without a need to have a permission. However, it doesn’t mean that the cartridge is standardized. Being in the public domain shouldn’t be confused with being a SAAMI standard. In the statement released on their Facebook page, MDWS’s CEO Mark Kexel says:

As you can see, the MDWS .277 Wolverine has grown leaps and bounds since it’s original launch just a little over 3 years ago. In fact, it has grown faster than most Wildcat cartridges that became SAAMI registered cartridges. We strongly feel SAAMI registration is just around the corner.

Considering that MDWS has also recently become a SAAMI member, I think chances are good we’ll see a new SAAMI cartridge soon.

MDWS has also released the chamber and gauge dimensions of the .277 Wolverine:

.277 Wolverine chamber dimensions

Dimensions of .277 Wolverine Go, No-Go and Field gauges

I think this is a very wise move by MDWS for a number of reasons. First, if somebody has designed a really successful new wildcat cartridge, but keeps it proprietary, it is a matter of time that a major manufacturer will make slight dimension changes and standardize basically a copy of that cartridge. Second, allowing other manufacturers to freely make the cartridge and products related to it (barrels, reloading dies etc.) will boost the popularity of the design and will be a good promotion of the original company that has introduced it.