You know how it goes, you’ve seen a few AR-15 builds, you’ve pretty much seen them all… until today!  We truly do live in strange times, when someone can build an AR-15 made to accept AK patterned magazines made to hold 6.5 Grendel cartridges, with the added feature of a side charging handle on the left side like the FN FAL. This particular AR-15 build was completed by Redditor Glenn but inspired by AP Smizzler’s thread on the 65Grendel.com forum.

The original forum thread was started by AP Smizzles asking about mating Palmetto State Armory’s KS-47 AR-15 lower receiver with a 6.5 Grendel upper receiver.  He also specified the use of Csspecs’ AK-47 magazines made for the Grendel cartridge.  Although Glenn didn’t start the thread, he latched onto the concept and put the theory to the test and made it work.  Glenn did have some troubleshooting to do, but with a little trial and error and a couple modifications, he ended up with a very unique AR-15 chambered in a hard hitting intermediate caliber.

Csspecs’ AKM Grendel magazines are available in 10, 20 and 30 round capacities.  According to Glenn, these magazines can be loaded to capacity and have been completely reliable.  Aside from the added cost of using these magazines over AR-15 patterned magazines, one positive aspect is the ability to load to standard capacities, compared to less standard 17 and 24 rounds per magazines.

Image credit: stores.csspecs.com

Several issues that needed to be addressed were how the magazine interacted with the bolt.  Glenn had to trim the feed lips on the 30 round magazines, but strangely enough, not at all on the 20 rounders.  Glenn also trimmed two of the bolt’s locking lugs to be able to clear the magazine due to how high it sits in the KS-47 lower receiver.  Below is an excerpt from Glenn’s range report:

Quick range report:

The 30 round magazine worked perfectly, no problems at all. The 20 round magazine did not like being used as a monopod — this caused the feed lips to interfere with the bolt. Shooting standing with no upward pressure on the 20rd mag worked fine. I shot 70 rounds of Wolf steel cased and 6 rounds of Hornady 123gr SST (brass cased, fed fine). No time to do accuracy testing.

The extractor on my Grendel bolt is weak. I will be adding an o-ring to start, and may swap out the spring if necessary.

The best combination of buffer/spring ended up being the AR10-length spring from PSA and a standard carbine buffer.

I’ve modded the 20 round mag feed lip as needed to allow shooting with upward pressure on the mag. More testing to follow!

The addition of the Devil Dog Concepts side charging handle gives a bit of an FAL flair to the whole thing as well.  You can view the original forum thread HERE, or Glenn’s Reddit thread HERE. 

What do you think about Glenn’s new 6.5 Grendel AR-AK pistol build?  Personally, I really like it.  It stands out as just unique enough, but still in a reliable configuration, as long as the right mods are done.  I’ve also been very interested in the 6.5 Grendel cartridge, but haven’t jumped in yet.  What would be a clever name for this muddy waters build?