Finally Picked Up a Polish PM63-C

[Combloc]

Magazines were produced in both 15 round and 25 round capacities and were generally serial numbered to the weapon with an electro pencil. Each original PM-63 appears to have been issued with one 15rd and three 25 rd magazines. Pioneer includes one of each variety but didn't bother to reserialize them so the ones you get will have random numbers. Both that came with mine were in excellent used condition. I also bought a few extra 25 round jobbers and the parts kit I bought came with one 15 rounder.

Here is an assortment of 25 round magazines:

I've placed these in order of finish condition with the best on the left and the worst on the right. All appear to be perfectly functional but you are buying decades old surplus so you have to understand that you're most likely NOT going to get unissued stuff. Having said that, the one on the extreme left has no serial number and appears NOS so that means there ARE still unissued examples out there but they are probably scarce. The next one in is the one that came with my pistol. The only one that showed any corrosion at all it the one on the extreme right and it's minimal freckling:



Earlier I said the magazines were "generally serial numbered to the weapon" but as always, there are going to be exceptions. One of the magazines I bought has clearly seen a fair amount of use yet has no serial number. Others show evidence of an earlier number being blued over and a new one applied. All I've seen have the number applied on the right front side but....well, I'm sure there are exceptions to this as well.

This picture shows you what I'm talking about:

The NOS is on the left. Next is "08612" but you can see an old number underneath ending in a "9". The one on the right is faintly marked "103290" and doesn't appear to have ever been renumbered.

Another on numbered "7938" but you can still see the stylus marks in front of the "7" from an old number which has been blued over:

The point here is that you're going to see the gamut on these things. Numbered, not numbered, renumbered, new, worn, a little rusty, you're going to see it all. BUT they are cheap at the moment. Buy a bunch and you're covered.

I currently have two 15rd magazines. The one that came with the pistol is on the right:


Notice that these have a little tab sticking out the front that's missing on the 25rd jobbers. This is to assist in removal as the 15 round examples fit almost flush with the bottom of the grip:

If you look closely, you'll see that the front of the pistol grip has a scallop machined into it so your finger can get a better purchase on the tab. Tab or no tab, all come out very easily. If they were any more loose, they would rattle.

The base plate on the magazine that came with the parts kit has seen better days but I'm sure it'll be an easy thing to straighten it out:



The vast majority of magazines you'll find are going to have the later style floor plate with the almost ubiquitous hole in the center that's locked in place by an inner plate with a protruding boss. But occasionally, you may run across a magazine with the earlier style floor plate which has a sprung finger that you have to pry up to remove:

Notice the serial number on the earlier style. Perhaps earlier magazines were only numbered on the floor plate? Or maybe they were numbered in addition to the body? I don't know. What I do know is that this one does not match the serial number on the magazine body so they didn't leave the factory together. I've not seen a later style floor plate with a serial number.


The only inspection marks I've found on magazines are at the lower front and they vary from magazine to magazine. Sometime though, you'll see the same mark on different magazines. This leads me to believe that you could trace a stamp back to an individual inspector. In other words, not only could you tell that the required inspection was made, but you could tell exactly which person did the inspection. Here are a few:




All seem to have a "KT/number" stamp at a minimum but others have additional stamps. Perhaps random magazines underwent additional inspections. We'll probably never know but it's fun to ponder these things. Someone else out there as weirdo as I am is probably already researching the topic.

 

[somd_mustangs]

I think that little projection at the back of the barrel is just to keep it from rotating and recenter it on going into battery. Maybe to keep from stressing the extractor too. FN 1922 has the same deal-io. Some of the other JMB blow-back designs don't though.

 

[Combloc]

That makes perfect sense to me. Thank you!

 

[somd_mustangs]

Good stuff!
I'd suspect the serial numbers on the mags are arsenal or unit-applied and not factory, hence the variety. Similar to the Russkie and E.G. Mak PM's.

 

[Combloc]

That makes perfect sense too. As always, you are the man with the answers!

 

[somd_mustangs]

Sometimes they're even right but not always LOL
Thanks for taking the time to do all the detail pics and descriptions!

 

[Combloc]

A disassembled magazine:

Getting it apart should be pretty obvious so I'm not going into that.

The follower is the craziest I've ever seen. To me, it looks like a miniature ultramodern house complete with a chimney:


The little window to the right of the chimney is where the bathroom would be.

In reality, the "chimney" is the bit that actuates the slide stop and it protrudes from a slot at the rear left top of the magazine:

We'll discuss the slide stop and how it works when we look at the frame.

Here's the same area pictured above but we've removed the follower so the slot is more obvious:

Notice also that the rear of the left feed lip has a little flat protrusion sticking up. That's the empty casing ejector. When we look at the frame, you'll see it's pretty tight in there and what with the safety/disassembly mechanism and the slide stop, space was at a real premium. So, they moved the ejector to the magazine. For this reason, you may find that your PM-63C is going to be magazine sensitive.

The floorplate:

This fits only one way and will not lock in place if installed backwards. The more pronounced and rounded protrusion at the right of frame faces to the front when installed.


And that's it for tonight.

 

[Combloc]

Sometimes they're even right but not always LOL
Thanks for taking the time to do all the detail pics and descriptions!

You're welcome. I enjoy this stuff.

 

[John from MD]

Excellent reporting!

 

[Combloc]

Thank you sir.

Tonight, we're going to look at the forward grip. We'll discuss what comes on the PM-63C, how it's been modified to be legal for importation, how it originally worked, how it's built, and whether or not it can be made to work again.

We'll start with a comparison picture between the parts kit and the pistol:

At bottom is the PM-63C. It's semi-automatic only and has been "permanently" altered to be a pistol. It can only legally be fired as shown; it's just a pistol. At top is the cut up parts kit of what was once a select fire PM-63 machine pistol with it's stock extended and the front grip deployed. Prior to destruction, it could be fired in both semi-auto and full-auto in either configuration shown. Of course, it also could have been used with the stock extended and the front grip folded or vice versa, thus giving you a total of four options in use. We'll look at the stock later. Right now, we're just looking at the front grip.

The first thing we need to do is remove it from the frame. Whether we're looking at the Pioneer pistol or a fully functional PM-63, removal is the same.

It's held on by two screws. The first screw is underneath. On the PM-63C, that screw is a phillips head that passes through both the locked in the horizontal position folding grip and the grip base before terminating in the frame. To remove it, turn it counterclockwise until it falls out:


On the machine pistol, it's in the same location but it's much shorter and is hidden under the folding front grip. First, press the button at the front of the grip base and rotate the grip downward until it locks:


Now we see a slotted screw that passe through the grip base only and terminates in the frame:

Remove it by unscrewing counterclockwise.

Here are both lower screws after removal with the Pioneer screw on the left:

Both are the same diameter and thread pitch.

The second screw is at the rear of the base on both models:

The screw itself is a simple slotted affair but, as you can see, the nut requires a special type of screwdriver. Fortunately, one was included with the pistol; it's at one end of the "T" handle on the cleaning rod:


It fits perfectly in the nut:

Remove by turning counterclockwise.

Screw, nut, and lock washer after removal:

Note the position of the lock washer for reinstallation and be careful not to lose it as it's pretty small.

Once both screws have been removed, the front grip assembly is ready for removal. If the stock is extended, you simply pull it downward and away from the frame. If the stock is stowed, the grip assembly must be first be slid forward until the steel lugs at the front of the base are clear of the stock arms as shown below:

After you've slid it forward, it simply pulls down and away from the frame.

A detail shot showing one of the steel lugs on the grip base clear of the corresponding cutout on one of the stock arms. The other side is identical:

It's a sort of French cleat arrangement that keeps the stock arms from flopping around when the stock is stowed.

Once thee grip assembly has been removed, take a look at the bottom of the frame where it was mounted:

The parts kit is at top. We can see where the front of the frame was torch cut and there appears to be a rectangular bar of some sort laying across the bottom of the frame. This is the sear. When you pull the trigger this part moves and releases the slide so that it can run forward under power of the drive spring, firing the shot. We'll look at it closer when we examine the frame. Notice that the sear has been entirely eliminated from the PM-63C. That's because it's now fired via an internal hammer.
In the same position on both examples, we see the screw hole for mounting the front grip assembly. On the original machine pistol, this hole is machined in steel because the entire frame is steel. On the PM-63C, the frame is a mixture of an original steel core mated to a newly manufactured aluminum component and this hole is machined in that aluminum component. It's also machined a little sloppily in the clearance department, meaning either screw (new, long Pioneer or original short) will wobble a little when screwed into the hole. Because there is a second screw holding the grip assembly in place at its rear, it's not a big deal when everything is assembled; the grip assembly doesn't move around. However, be VERY careful not to overtighten this screw on the Pioneer pistol when reassembling because I have a pretty good hunch it'll be easy to strip this hole out. Exacerbating the problem is the fact that it's in aluminum, making it even easier to strip. Pioneer could have done better here. They should have placed a steel insert into the aluminum and more precisely threaded it.


Alrighty both front grip assemblies are off, now what?

We'll continue in the next post and I'll tell you now, the Pioneer grip can be made to work again as long as you do it legally.

 

[Doctor_M]

This is just freaking awesome. Thank you for sharing in such detail!!

 

[Combloc]

You're most welcome sir.

 

[Combloc]

UNLESS YOU WANT TO LAND YOURSELF IN ALL KINDS OF TROUBLE WITH OUR ETERNAL FRIENDS, THE ATF, READ THIS ENTIRE POST BEFORE MESSING WITH YOUR FRONT GRIP ASSEMBLY AND FOR HEAVEN'S SAKE, DON'T INSTALL ONE ON YOUR PM63-C WHICH HAS A DEPLOYABLE FRONT GRIP BEFORE READING THE ENTIRE POST.

REPEAT, UNLESS YOU WANT TO LAND YOURSELF IN ALL KINDS OF TROUBLE WITH OUR ETERNAL FRIENDS, THE ATF, READ THIS ENTIRE POST BEFORE MESSING WITH YOUR FRONT GRIP ASSEMBLY AND FOR HEAVEN'S SAKE, DON'T INSTALL ONE ON YOUR PM63-C WHICH HAS A DEPLOYABLE FRONT GRIP BEFORE READING THE ENTIRE POST.


Annnnnnnd, we're back. We left off with the front grip assemblies removed. Now, we're going to disassemble them, see whether or not the one that came with the Pioneer pistol can be made to work again, and just talk about the parts are built in general. We'll start with the unmolested one that came with the parts kit:



The front grip assembly is comprised of five parts. They are the base, the grip, the locking bar, the locking bar spring, and the locking bar nut. To start disassembly, we again break out the specialized screwdriver on the end of the cleaning rod "T" handle:


Turn the nut counterclockwise to remove it. If it's a little tight, you can position the cleaning rod at a 90° angle to the "T" handle and use it for leverage. Just be careful the screwdriver doesn't slip out of the nut and bung it up:



Then the locking bar spring will just lift out:


Next, press the threaded end of the locking bar with your thumb and it will just fall out the right side of the front grip base:


To finish disassembly, the front grip simply pulls away from the base:

The whole mechanism is a dead simple push button design. If it's not already obvious to you how it works, it'll sink in when we look at the individual parts.


Now, can we disassemble the front grip assembly on the Pioneer pistol and, more importantly, make it functional again? Regardless of what you might have read or heard elsewhere, the answer is yes, we can.
As before, we start with the assembly removed from the pistol:

If you push on the button (locking bar nut), nothing happens. It won't budge.

Break out your trusty screwdriver again:


And remove the nut as on the unmolested grip assembly:


This time, you won't find a spring inside but rater, a steel sleeve. You may have to shake it out of the grip base but it's in there and it'll come out:

This sleeve is why you can't press the button. On the other grip, when you press the button (which is screwed to the locking bar and thus rigidly affixed to it), you compress the spring and push the locking bar out of engagement with the grip, allowing it to rotate down. With this sleeve replacing the spring, you can't disengage the locking bar from the grip so you can't unfold it.

As with the other grip assembly, the locking bar will now easily press out of the base:


And finally, the grip will pull away from the base, completing disassembly:



Now, using the steel sleeve, you can reassemble the Pioneer grip to the base in the deployed position. Of course, it'll be locked in this position because you can't press the button. Alternately, you can replace the steel sleeve with the spring out of the other unit and enable the push button again. Or, if you don't have an unmolested grip assembly to rob parts from, you can always head to your local hardware store and buy a spring that properly fits into the hole in the grip base. It should be just a tiny bit smaller than the diameter of the hole in the base and it should extend just a bit past the opening when at rest. Use the picture above for reference. If the diameter of the spring is too small, it won't catch on the internal shoulder and be pointless. In that case, the locking bar would have no tension on it and it would just slide back and forth in the base. If the spring diameter is too large, well, it obviously won't fit into the base. If it's too long or too short it won't work either. When you're looking for your spring at the store, just be thinking about Goldilocks and the Three Bears. It doesn't have to be a super strong spring either. It only takes about 7 or 8 pounds of pressure to fully compress the original spring.
Anyway, when you're done, you'll have a functional front grip:


It'll have an unsightly hole in the grip but beggars can't be choosers pal:



NOW..........READ THIS NEXT PART!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

THIS PART IS IMPORTANT. YOU CANNOT, REPEAT CANNOT, INSTALL THE FOREGRIP ASSEMBLY IN EITHER THE LOCKED OPEN POSITION OR WITH AN OPERATING PUSH BUTTON ON YOUR PIONEER PM-63C UNLESS YOU HAVE FIRST REGISTERED YOUR FIREARM WITH THE ATF AS AN NFA ITEM. IF YOU DON'T KNOW WHAT I'M TALKING ABOUT, TALK TO AN FFL YOU TRUST, PREFERABLY ONE WHO IS LICENSED BY THE ATF IN THE SALES AND/OR MANUFACTURE OF NFA ITEMS. IF YOU INSTALL THE GRIP ON YOUR PIONEER PM63-C IN EITHER THE LOCKED OPEN POSITION OR WITH AN OPERATING PUSH BUTTON WITHOUT FIRST REGISTERING IT WITH THE ATF AS AN NFA ITEM, YOU ARE COMMITING A FELONY WHICH, AT A MINIMUM, WILL BAR YOU FROM EVER OWNING A FIREARM FOR THE REST OF YOUR LIFE. AT A MAXIMUM, IT WILL ALSO LAND YOU IN FEDERAL PRISON FOR UP TO TEN (10) YEARS WITH A SIZEABLE MONETARY FINE. YOU HAVE BEEN WARNED.


IN CASE YOU DIDN'T CATCH IT THE FIRST TIME....

YOU CANNOT, REPEAT CANNOT, INSTALL THE FOREGRIP ASSEMBLY IN EITHER THE LOCKED OPEN POSITION OR WITH AN OPERATING PUSH BUTTON ON YOUR PIONEER PM-63C UNLESS YOU HAVE FIRST REGISTERED YOUR FIREARM WITH THE ATF AS AN NFA ITEM. IF YOU DON'T KNOW WHAT I'M TALKING ABOUT, TALK TO AN FFL YOU TRUST, PREFERABLY ONE WHO IS LICENSED BY THE ATF IN THE SALES AND/OR MANUFACTURE OF NFA ITEMS. IF YOU INSTALL THE GRIP ON YOUR PIONEER PM63-C IN EITHER THE LOCKED OPEN POSITION OR WITH AN OPERATING PUSH BUTTON WITHOUT FIRST REGISTERING IT WITH THE ATF AS AN NFA ITEM, YOU ARE COMMITING A FELONY WHICH, AT A MINIMUM, WILL BAR YOU FROM EVER OWNING A FIREARM FOR THE REST OF YOUR LIFE. AT A MAXIMUM, IT WILL ALSO LAND YOU IN FEDERAL PRISON FOR UP TO TEN (10) YEARS WITH A SIZEABLE MONETARY FINE. YOU HAVE BEEN WARNED.





That's it for this post. In the next one, we'll look at the various components which make up the front grip assembly. If you've studied the PM-63 at all online, you've been told by reviewers that the front grip is fragile and prone to becoming sloppy loose or worse, breaking off. Welllllll, we'll talk about that.


THIS LAST SENTENCE OF THIS POST IS A CYA STATEMENT. READ THIS ENTIRE POST BEFORE YOU EVEN THINK ABOUT BEMOVING THE FRONT GRIP ASSEMBLY THAT CAME FROM THE MANUFACTURER INTALLED ON YOUR PM-63C.

 

[clandestine]

Great post as always. Thanks for sharing.

 

[Combloc]

My pleasure. It's sad that I have to put the lousy legal statements in there but it's the world we live in unfortunately.

 

[Vile Shadow]

Dammit @Combloc you always find the cool stuff

One day I wanna see your gun vault

 

[Waingro]

My pleasure. It's sad that I have to put the lousy legal statements in there but it's the world we live in unfortunately.

Agreed Beautiful pictures either way

 

[Robert2888]

Awesome post and pictures, as usual. I have to say that trying to build out this from a kit into a semi, has been extremely difficult…to put it lightly.

 

[Combloc]

Thank you guys!

Now, we are going to take a closer look at the front grip assembly. Like you, I've seen a number of videos, all in English and all done buy guys who never served in the Polish military with a PM-63 that was issued to them. The general statement about the front grip is that it's "just plastic", "fragile", and "gets loose with use". I'm to believe that it's clearly almost an afterthought and is of dubious use. Well, I think that sometimes, one person makes a judgement call about this or that and everyone else in the crowd just pig piles on. Am I saying those folks are wrong? I am not. I'm also not saying they are correct. I am saying that Warsaw Pact Poland was known for producing Quality small arms for their troops. That leaves me wondering......if the front grip was really so fragile and prone to wear, would the Poles have used it for decades unchanged and wouldn't all of these parts kits coming in have floppy, or outright broken grips?

The first thing you need to know is that both the base and grip aren't just molded plastic. Like MANY very successful designs by MANY very successful manufacturers, the plastic is molded around a steel armature. This method of manufacture allows parts to inexpensively sport a complex shape while also being rigid, robust, and lightweight. It's simply the norm in today's military small arms manufacturing but it was still pretty new and bold when the PM-63 was accepted for service.

In the pictures that follow, we'll mostly be looking at the parts that came with the parts kit because the bluing wear makes it easier to spot where steel ends and plastic begins. But there might be some shots of the assembly that came with the PM-63C mixed in there too. Which one we are looking at in any particular picture is generally irrelevant. We'll start with the base. The most obvious use of steel in that part is the locking bar slot:

Notice the "Y" inspection mark. The right side of the steel locking bar slides back and forth in this slot when you press the button to unfold the grip. The slot also takes some of the torsional forces when the grip is deployed and being used, such as during firing or running. In other words, when you're torquing on the grip, you're doing so through a steel bar anchored in a steel insert molded into a plastic form.

We also find steel on both sides of the base at its top front. At these places, we have a steel half dovetail molded into the plastic to act as front anchor points for the stock arms when it's stowed:


Stock on parts kit here slid partially to the rear for clarity:


Front view of right side steel insert:


Detail of left side illustrating how plastic has flowed through two holes machined into the insert:


Inside view showing reinforcement of where front mounting screw passes through the base:

However, a magnet does not show attraction in this area so I doubt any steel is present here.

Moving on to the grip proper, here we see the inside/rear (depending on whether it's stowed or deployed) of the grip that came with the Pioneer pistol

Notice all the metal shavings. These came from pioneer drilling a hole through it for the front mounting screw. They went lazy and didn't even bother to clean them out. You can be sure I did but I wanted to take a picture of it the way it came so that you know what to expect should you disassemble yours. Anyway, with the exception of the extreme bottom of it, a magnet sticks to this thing just about anywhere I check. Were you to melt the plastic off of the grip, it would look like a miniature two rung ladder. Steel runs all the way down both sides of it, forming the rails.
We can see the top "rung" here to the right of frame just in front of the round ejector pin mark:


And in this picture, the bottom "rung" is just to the right of and being touched by the tip of the screwdriver:


Screwdriver removed revealing another ejector pin mark:


The majority of the steel side rails in the grip are invisible to your eye, being buried in the grip's plastic envelope. However, they become visible when they emerge from the top of the grip and form the attachment points for mounting the grip to the base. At this point, another layer of steel is spot welded on, for added strength. In this shot, we can clearly see the two layers of steel:

This area, and the corresponding steel insert in the base we looked at earlier is where the vast majority of stress occurs when the grip is in use. Laminating it like this makes it stronger than if it were solid, which, if I understand things correctly, would be more prone to cracking.

The left side attachment point showing four spot welds and another inspection mark:

The inside diameter of the hole is filled by the locking bar nut when assembled ensuring that we have steel on steel contact at all times.


The right side attachment point is pierced by two slots forming a cruciform shape:

Again, note the four spot welds. When the grip is stowed, the locking bar passes through the vertical slot and terminates in the steel insert molded into the grip assembly base. When the grip is deployed, the locking bar passes through the other slot and again, terminates in the steel insert embedded in the base. It's important to note that the locking bar at no time rotates; it only slides back and forth in the base under tension of the locking bar spring. When you press the grip actuating button (locking bar nut), the locking bar slides to the right and out of engagement with right side grip attachment point, allowing the grip to rotate around the locking bar.

Detail of the locking bars from both the PM-63C (bottom) and the PM-63 (top) with relevant parts assembled to them:

Inside the grip base where we can't see them well enough to get a good picture with old photographic equipment, we have a left shoulder and a right shoulder. Regarding the operable pushbutton on the PM-63, the left shoulder comes into play when you press the button/locking bar nut to actuate the grip. You can only press the button and compress the spring so far before being stopped by the left shoulder; just far enough to disengage the locking bar from the grip's right attachment point, thus allowing it to rotate into either the deployed or stowed position. Similarly, when the button is released, the right shoulder in the base comes into contact with the inside flattened part on the right side of the locking bar, stopping it from moving too far to the left, just far enough that the extreme right edge of locking bar will be flush with the right side of the base when the grip is properly stowed or deployed. WoW!! That's a LOT of explaining there!! Hopefully all of it makes sense because that's the best I can do.
Regarding the PM-63C, the steel sleeve in place of the spring locks everything up in the base so that the pushbutton is deactivated.

After looking at all of that, I'll give you my personal thoughts on the durability of the front grip. You have to have a bit of tolerance built into the moving parts of the grip. If it were made to tight tolerances, you'd have reliability issues. This means a little bit of movement both when the grip is stowed and when it's deployed. My parts kit is all numbers matching and the furniture that came with it has a matching patina so I think it's fair to say that both the parts kit and it's forward grip have seen a lot of use over the past 52 years. The front grip assembly the came with my Pioneer pistol looks to be new old stock. However, when removed from the pistol and restored to working condition, it exhibits EXACTLY the same amount of play as the same assembly that came with the parts kit. This leads me to believe that the rumors of fragile grips that won't hold up with use are greatly exaggerated.

Now, could I go gorilla and twist on a deployed grip to the point that it would break? Yes, I'm sure I could but that would constitute abuse, not use. Could I run with scissors, er, I mean machine pistol, take a tumble, and break the thing in the process? Absolutely I could. I could also do the same thing with the stock on my Czech VZ-61. You can break ANYTHING with enough abuse or during an accident.

So, in the end, here's my verdict. Is the front grip assembly as durable as the folding stock on my Chicom 56S-1? Nope. Does that mean it's prone to breakage? I don't get the impression it is under normal use. Will it get more and more loose with use? Probably. I'm sure the stock on my trusty 56S-1 isn't as tight as it was 35+ years ago either but it's so insignificant I don't notice it. So in Polish, here's what I think about it all.

Działa dobrze w obecnej formie.

Your milage may vary. Next time, we'll discuss the stock.

 

[Combloc]

Next up is the stock. I'll show you how it works, what's been done to the PM-63C to make it inoperable, and whether or not it can be made to work again if you register your firearm with the alphabet boys as an SBR.

For reference, the picture below shows the parts kit up top with the handgrip and stock deployed and the Pioneer pistol below:


Since the stock doesn't work on the PM-63C, we'll have to use the parts kit to show you how one actually works on an original PM-63 machine pistol.
We start with the stock release lever at the right rear of the frame.

This is the later version of the stock release. On earlier versions, it was mechanically different being more of a push button but regardless of which version you encounter, they do the same job. That job is to keep the stock stowed until you want to use it.

When we turn the pistol upside down to look at the release lever from the bottom, it becomes obvious how it works:

The lever is stamped steel with a little spring inside and it rotates on the visible axle pin. Press on the rear of the lever and the front of it disengages from the divot machined into the right side stock rail, allowing you to pull the stock to the rear.

Ok. To deploy the stock, you begin by pressing the rear of the stock release lever shown above. While keeping the lever depressed with one hand, use the thumb and forefinger of your other hand to grasp the splined area at the rear of both stock rails and pull to the rear. Once you've reached the position where the butt plate is clear of the frame, you can relax pressure on the stock release lever:


Press up on the butt plate and it will begin rotating freely around a pin connecting the rear of the stock arms. Here, it has been rotated 90°:


Keep going. we've rotated it 180°:


Once you're rotated it 270°, it'll encounter built in stops and will rotate no farther:

Note: there are no detents locking the butt plate in any position. It will freely rotate through 270° of arc.

Now, pull the stock fully to the rear:

You'll hear an audible "click" at this point, letting you know the stock is locked in the open position.

Finally, rotate the stock downwards until the stock arms contact stops machined into the frame. The stock is now fully deployed and ready for use:

Note: Although the stock locks open, it does not lock in the slightly depressed position shown above. It will freely rotate between the horizontal and slightly depressed positions in use.

With the stock deployed, we can see the area on the bottom rear of the frame that was previously covered by the butt plate:

Notice all the milling marks. I guess they figured there was no point in cleaning this area up because it's normally not seen. But that's not what we're here to look at. The main reason we're here is to look at the button we need to press to stow the stock. That button is the little square with most of its bluing missing just to the left of the center of the picture. That's what we need to press. When we do so, we are, in fact, pressing on the entire locking piece that holds the stock open. We'll see how that works in the next post when we disassemble the stock assembly.

So, to stow the stock, rotate it up to the horizontal position:


Press the button on the locking piece located at the bottom rear of the frame:


While holding the button on the locking piece depressed with one hand, use the thumb and forefinger of your other hand to grasp the splined area at the rear of both stock rails and begin pushing the stock forward. After about a half inch of travel, you can relax pressure on the locking piece button. When the stock is approximately 3" from the closed position, rotate the butt plate 270° to the horizontal position:


Continue pushing the stock forward until the stock release lever engages the divot milled out of the right side stock rail. You will hear an audible "click":

The stock is now stowed and locked in the closed position.


That's enough pictures for one post. We'll disassemble the stock in the next post and see how it works.