Have you ever typed AK47 Rifle Stock Fix into Google? There is not much there even though the under folder stock models of the AK47 family are terrible, everyone knows it. Even all the die hard AK47 fanboys (myself included) will tell you they just suck. If Uncle Ivan or whoever could have made a cheaper more uncomfortable stock for Mother Russia he would have. The ergonomics, the cheek slap, the cold metal sticking to your cheek in winter none of it is pleasant. The complaints go on and on, even if you get a well built AK family of rifles with a tight under folder its still the same with just less wiggle.
That’s were the guys at Definitive Arms have stepped in to fill a void in the AK47 accessory market with the introduction of their new UFM4-AKMS stock adapter. Definitive Arms is a St. Petersburg, Florida based manufacturer of an entire line of AK rifles and accessories.
I first became aware of the guys at Definitive Arms while watching a review on their muzzle attachment known as the Fighter Break. RobSki over at the AKOperators Union Local 47-74 had put one threw a series run of torture via a select fire AK variant a few months ago. I thought to myself if their muzzle break can handle that and reduce felt recoil, then what else did the company have up their sleeve.
What’a the Big Deal ?
That’s a common question a lot of people ask who have never shot an under folder, others say “deal with it“, I prefer to go the other route. I chose to find a way to turn a gun that was unpleasant to shoot, although ridiculously reliable into something that was more user friendly and still had the same AK47 durability. The UFM4-AKMS kit basically allows you or a gunsmith to remove the folding stock mechanism and install a block onto the rear trunion allowing the use of a AR15 style buffer tube, castle nut and endplate. This allows the shooter to get a much more comfortable and consistent cheek weld, resulting in a better sight picture. In a nutshell If we eliminate or lower the uncomfortable factor a shooters might experience we naturally increase their chances of being more accurate.
What’s Included and What’s Needed ?
What’s in the bag when the UFM4-AKMS kit arrives? It’s a pretty simple list, the M4 trunion block, four screws and four nuts with you guessed it four roll pins. Inventory of the pack was the easiest part of this whole kit. In order to complete the project you will need to have the following complete list
- Blue Loctite
- 3/8″ combination wrench
- Flathead screwdriver to remove pistol grip
- Selection of roll punches and regular punches
- A laptop (HIGHLY encouraged)
- Tray for parts
- Eye protection
- Needle nose Pliers with thin head
I will give credit right up front to a particular You Tuber named Black1705f without whose help I would have been lost, if you are attempting this be sure you click the link at the bottom labeled “Take Down Video” it will take you to the link for the slow break down of the rear of the under folder AK47 stock. This is pretty straight forward if you have any mechanical abilities and can watch a You Tube video, I think it took me about six minutes to get this coming off the rifle. I was fortunate, some of you may want to prep the metal with some penetrating oil to ease in the pins removal.
Remember to go slow and not lose any of your parts, also remember that things like the push button stock release are under pressure and when a roll pin is released, that pressure has to go somewhere an we prefer it not go into your head. This is another reason to go slow and wear eye protection.
Installation of the block is can be relatively easy, but with that said the rear bolts being the harder of the two sets to install, I suggest you start with the rear. My first step was to separate the contents of the bag, two bolts and two nuts per side, and made sure I didn’t lose the roll pins that would be installed later. This is the part of the process where the blue Loctite comes into play, add a small amount to each of the four screws and prepare to insert them. This next part is a section that can drive a person crazy if they don’t go slow and have some patience. I found it easiest to use a set of long needle nose pliers to hold the 3/8″ head of the nut in the receiver body and use my opposite hand to turn the screw from the outside with a 1/8 allen wrench. Once a few threads were started I inserted the 3/8″ combination wrench into the receiver and proceeded to tighten the screw.
The method I used was to get the back two tapered screws started then insert the front two screws just to prevent shifting during the build process. More than once I have tried to assemble things to find out a hole wasn’t drilled correctly or something settled out of alignment, I wasn’t taking that chance. Better to go slow and be safe than rush the install and screw something up. Once the back screws were tight I removed the front screws, applied loctite and repeated the same process.
Once you have the four screws and nuts securely fastened with loctite, hopefully without stripping them out, its time to drill and set your four supplied roll pins into the receiver. This part for me causes a great deal of frustration, not because of drilling into my AK receiver but because I hate roll pins with a passion. If there is one problem with any gun project wether it be my PPS43 or an AR15, it’s always roll pins that screw my projects up and make me descend into a tirade. So you can understand my anxiety and frustration with having to drill and set them on this gun.
Measure twice, drill once as the old adage goes but in this case it was drill four times. Using my trusty Dewalt 12 volt drill I made all four holes clean and straight as I could. I applied a little bit of Slip 2000 to the roll pin hole, because that is what I had close for lubricant, I aligned the pin and slowly began to tap. The roll pin slid into its hole all the way very easily and I was relieved, only three left to do. I completed one side of the UFM4-AKMS mount and flipped the rifle over and completed the next pin, then IT happened. While attempting to complete the final roll pin installation I got overly cocky and something terribly wrong happened, as I heard an odd sound with the hammer strike.
Clearly seen above is what happened when you screw around and get cocky with something small like a roll pin. Luckily I dug threw my boxes of weird parts and found another one and with a little more lube and a lighter slower striking method I got the fourth and final roll pin installed fleshly and cleanly in the Definitive Arms UFM4-AKMS luckily I didn’t damage anything in my rush to completion.
The final steps of the build were the easiest yet, steal a M4 tube, and castle nut from my wife most recent AR15 build and install it on my previously under folding AK47 rifle. I had this part of the installation done in no time at all, I was familiar and experienced with installing buffer tubes and castle nuts. Pretty straightforward stuff and the end of the build. Using a DPMS AR15 armorers tool i secured the needed components. I slid on the also stolen B5 AR25 stock onto the tube and continued to reassemble the now very different looking Polish AKMS/AK47.
The rifle feels very different from what it was an hour earlier but it seems to point and feel much more natural than the wire under folder that was previously on it. The B5 stock and UFM4-AKMS kit does allow a much more relaxed sight picture for a shooter to view, we shall see this weekend during some planned trials.
All told if you have an hour of your time and a modest amount of mechanical skills you can easily complete this project. The video listed below was invaluable in my disassembly of the under folding mechanism. If you were like me and trapped in a AK47 under folder that you hated to shoot, there is hope for you. Definitive Arms is releasing these for both regular under folders and Yugoslavian pattern under folders. The Yugo variety should be shipping next week I am told.
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Links to People Who Helped