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The AR-47 Project: A New Hope
By George Ross Jr. January 12, 2021

The year 2020 ushered in a new way of thinking for shooting enthusiasts at least it has for me. I was never one to keep a bunch of ammunition on hand as it was plentiful and less expensive in years gone by. When the ammunition shortage of 2020 hit I was woefully unprepared. I had to do something since firearms with no ammunition are just pretty paperweights. I used the opportunity as a good excuse to invest in yet another rifle. I started to look at what ammunition was left on the shelves at my local stores. I was looking for something to fill the gap that the lack of .223/5.56 had left in my plinking habits. Around these parts the ammunition that was both plentiful and cheap was 7.62x39. And so an AR-47 was born.

Wait just a minute isn’t the 7.62x39 the “Bad Guys” cartridge. I will admit I was biased towards 7.62x39 at first. This wasn’t the first time I had contemplated using the cartridge. 7.62x39 was one of the considerations I had when I built my 6.5 Grendel AR-15 for deer hunting. The big reason I didn’t use it at the time was that 7.62x39 falls like a rock at ranges beyond 300 yards when compared to the 6.5 Grendel, but this time since 7.62x39 is on the shelves in my area and sort of cheap I decided to take the leap. Read on to see why I’m mostly glad I did.

The Build

As this was my first foray into the 7.62x39 world I decided to go for a “budget” type build to familiarize myself with the cartridge. Here is a list of the parts used to build this unholy union of Russian and American technologies.

At the Range

Once I finally got to shoot the 7.62x39 is was pleasantly surprised. I was expecting more recoil from the combination of the carbine length gas system used in the Bear Creek upper and larger cartridge. The buffer and buffer spring I used in this build definitely did a good job of mitigating recoil and smoothing out the cycling of this rifle. All of the spent casings consistently eject at 4 o’ clock. Even an elder rifle builder at the range I frequent was inquiring as to how I had gassed the rifle. I let him know I used mass. Since the Bear Creek upper I used was doing a fine job cycling brass ammo. I set about getting this rig zeroed in. I went with a 50 yard zero. Once that was accomplished the rifle was battle accurate between 50 and 300 yards. With the way this rig shoots I am able to spot my own shots through the scope. I tried hitting some steel out to 400 yards and I could clearly see where the bullets were kicking up dirt way in front of the target. I only took a few shots out that far to see if 7.62x39 drops like a rock beyond 300 yards and indeed it does. One would have to upgrade the scope to shoot this rifle beyond 300 yards.

In the picture above you see the two 50 yard targets that were set up to get some rough numbers. I used a 25 foot tape measure to measure each five round group. This is not the most accurate way to measure, but my shooting isn’t accurate either. With groups like these what is a thousandth of an inch amogst friends? Armed with my meager skills I was able to get one group that was 1.192” (1.5”-.308” width of bullet) and another that was 1.692” (2”-.308” width of bullet). This is an average of 1.442”. These are not even close to MOA groupings. But even though my groupings were pretty big at 50 yards I can still regularly hit 4” steel out to 250 yards with this rifle. These results were achieved using GECO 7.62x39 Target FMJ 124 grain. I really took a liking to this ammunition. Below is a picture of the range I was shooting at.

Problems Encountered

As is the case with most things in life it wasn’t all cookies and ice cream. 7.62x39 was not designed to work with AR-15’s it was designed to work with AK-47’s. So problems were bound to happen.

So the biggest issue that was encountered was with light primer strikes on steel cased ammunition. The M*CARBO trigger spring I bought for this build will not set off Berdan primers with any regularity. I even tried a Timney 668-S 4 pound trigger that I use in the aforementioned 6.5 Grendel deer hunting rig. It would not fire Berdan primers. I have used .223 steel case ammunition before, but it was in a rifle with a mil-spec trigger. So I swapped out the M*CARBO trigger spring with the PSA mil-spec trigger spring. This yielded much better results, but I still have the occasional light primer strike. I was however hoping for a little better trigger than mil-spec, but these are perilous times we live in. So if I want to be able to fully take advantage of the steel ammunition on the store shelves I’m gonna have to get this light primer strike issue resolved. The primer in the below picture was struck twice using the PSA mil-spec trigger spring and it did not fire. Updated January 17, 2021: This issue has been resolved. The Black Rifle Arms AR-15 7.62x39 Enhanced Firing Pin did the trick.

Another issue that was encountered was with the E-Lander 17 round magazine I bought for this build. It will only accept 16 rounds of 7.62x39 as opposed to the 17 that is advertised. It was so hard to get the sixteenth round in I didn’t even try to fire the rifle with the magazine loaded with 16 rounds. I feel as if this is a minor issue as I have heard of 7.62x39 magazines that will not reliably cycle rounds at all. Cycling is not a problem for the E-Lander magazine when it is loaded with up to 14 rounds of brass or steel cased ammunition. I normally just load 10 rounds in this magazine. An interesting side note here is I can load 18 rounds of 6.5 Grendel into the magazine. I guess the lesson here anything above 10 rounds and the tapering of the 7.62x39 case starts to require a more pronounced curve in a magazine. The below image is a good illustration of why this is so.

An Unexpected Surprise

I learned that for the most part that 7.62x39 and 6.5 Grendel 10 round magazines are interchangeable and I used a 10 round E-Lander 6.5 Grendel magazine to verify this. There were no problems using the 6.5 Grendel magazine loaded up with 7.62x39. In the pictures below you can see two 10 round E-Lander magazines side by side. The only difference I can see is the engraving on the sides that mark the caliber.


Final Thoughts

When I started the AR-47 project in October 7.62x39 ammunition was everywhere in these parts. It seems I wasn’t the only one with the bright idea to use what was on the store shelves. Because as of now 7.62x39mm ammunition is in short supply. Just about all the that remains on the shelves in the stores around here is shotgun shells or .450 Bushmaster. 7.62x39 ammunition can still be found more frequently than .223/5.56, but I haven’t seen either in a brass case in a store for at least a month now.

Aside from the light primer strike issue I need to resolve (Updated January 17, 2021: This issue has been resolved. The Black Rifle Arms AR-15 7.62x39 Enhanced Firing Pin did the trick.) I am pleased with the AR-47 that I have built and the 7.62x39 cartridge it uses. In this AR-47 I have discovered a well rounded rifle that is capable of fulfilling more than one role. The 7.62x39 is a good plinking cartridge out to 300 yards, it is also good for hunting medium sized game out to 250 yards using select ammunition, and it would suffice as a self defense cartridge with more knock down power than .223/5.56. I am glad that through the turmoil that is the current ammunition shortage there exists alternate cartridges that can do the job. Provided you are willing to drop some preconceived notions and fork your money over to the Russians. So ask yourself this. Are you BETTER RED THAN DEAD?