MAGPUL STR NON DESTRUCTIVE REVERSIBLE PINNING

Got an STR and love it. Free state is in my future some day so I elected not to destroy the tube or the stock. Very simple but involves a little work. In the end, you have a stock and tube that has not been altered in anyway and if you are smooth with the tools, you could de-mod it and sell it back to MAGPUL with out them even knowing.
This will most likely work for any Magpul stock that uses this type of adjustment mechanism. But I only have the STR. For less complicated stocks, just skip the rivets/frictionlock/battery tube comments and go to work. It might be wise to take additional steps to ensure compliance with AWB requirements in this and all cases. This procedure is theoretical, for reference purposes only, and in no way assumes or provides liability or legal advice.
Time needed, 30-45 minutes to figure it out and complete the project…
TOOLS NEEDED:
Flat head
Drill with assorted bits
Pop rivet squeezer and rivets
AR-15 assembly punches or equivalent
Diagonal cutters or equivalent
Dremel rotary tool with cutting wheel or equivalent
Universal problem solving device
ADDITIONAL MATERIALS NEEDED:
1″ Aluminum rod stock or, you guessed it, equivalent
Little tiny zip lock baggy
First, choose your length of pull adjustment and mark it or just remember where you want it.
Remove the two allen screws holding the but-pad to the stock. Pop the battery storage caps off. With the flat head you can push in the tangs that hold the but pad captive to the back of the stock and set that and its hardware aside. With the battery storage caps removed, you will see a single pop rivet on each side at the aft end of the stock. Drill the rivet out. Choose a drill bit that is just a little larger than the gap in the middle of the rivet. You will see a cylindrical channel running through the middle of the rivet. You want to drill out the wall of that channel without touching the plastic of the stock on the outside of the rivet. Start small on the drill bit, too big and you risk getting into the plastic of the stock.
When you have drilled enough, the little ball-bearing will drop out of the back side of of the rivet. Careful with the drill here so you don’t drill into the nut plate mount for the but-pad attach screws. If the rivet starts spinning with the drill, just wedge that flat head in there to keep it from spinning until you get all the way through. If you picked the right bit and drilled just right, a punch will pry the head of the rivet off the shank and allow you to remove the head of the rivet and discard. For 90% of the time, you will need to use the diagonal cutters (dykes) to bit the head of the rivet off.
Now it gets a little ugly. Due to the but-pad attach screw top nut plate mount’s proximity, you can’t simply push the shank of the rivet through the hole to remove it. Here I used a combo of flat head, punch, drill and universal problem solving tool to mash the hell out of the shank of that rivet to get it out. Just beat it up until you are able to scrape, crush, pry or beg that little bugger out of the stock.
Once the rivets are cleared out, you can remove the entire battery storage tubes completely. In fact, once you get the top half of the rivet out, you can probably get the tubes out of the way so you don’t damage them. They slide aft to disengage from the stock and require no further disassembly to remove. You might consider using the tubes to store hardware and roll pins for later….
With the tubes removed, we can now go to work.
Lets remove the ‘friction lock’. Just tap out that forward roll pin and save for later. Once that pin is out, you need to pry and scrap the friction lock off the stock. Careful here. Try to get two long flat-heads in here. At the aft/long end of the friction lock you will see a little slot in which to slip in a flat head and pry it wider for removal. The roll pin underneath these slots is oversized/long and if you are not careful will gouge the inside of the friction lock pretty heavily. I didn’t see this at first and damaged mine a little so watch out. (in the end the scars are on the inside and it its still functional so don’t stay up late worrying about it Take it easy and use a 3rd hand)
With the fric-lock removed, the oversized/long roll pin holding the length of pull adjustment mechanism plunger captive is ripe for harvest. Careful here, you’ll need that spring some day… and your eyeball. I used a spare punch to block the exit of the spring through the cavity used to install the stock onto the tube. Knock that sucker out and retrieve the hardware from the adjustment mechanism.
Take the spring from inside the adjustment mechanism, get a little zip-lock baggy, drip a bunch of gun oil and seal it inside for later. Much later…
Now, get your dremel and aluminum rod. Cut a piece that is roughly 3/4″ inch long. Go a little long here. The reason I like aluminum not steel, is the ease of working with it. Cut and shave the rod to fit into the adjustment mechanism where the spring used to reside.
View attachment 41164View attachment 41165
As you shave the rod down, keep test fitting the rod into the adjustment mechanism. Remember, the spring is removed and does not go back into the stock. Keep in mind, when test fitting the length of the aluminum rod, there is a channel in the cross rod on the adjustment mechanism. To get the tightest fit, apply some pressure to the bottom of your aluminum rod to ensure that the cross bar is oriented properly. Otherwise, your rod will be too long/short when final assembly time comes.
This part is really up to you. How much wiggle do you want in the adjustment lever? If you don’t care or aren’t picky, just cut a piece that keeps the plunger from disengaging from the buffer tube and you are ready for assembly. I didn’t want any wiggle, so I shaved it down so that the oversize/long roll pin didn’t quite fit back into the adjustment mechanism. Then I used the universal problem solver against the side of my punches to compress a channel into the face of the bar stock for the roll pin to fit into. This made the lock up completely immobile, no wiggle or give when the adjustment lever is pressed.
View attachment 41166View attachment 41167
Now, I won’t bore you with the reassembly procedure because it is just the reverse of what we just did.
REMEMBER: THE SPRING DOES NOT GO BACK INTO THE ADJUSTMENT MECHANISM/PLUNGER!!! If you cut your aluminum rod to accomodate the spring as well, you are probably wrong, and probably won’t get the thing back together again… But feel free to attempt it Take the little oiled up baggy you have your spring in and throw it in the stock cavity behind the buffer tube before you close it up with the but-pad
View attachment 41170
Now, I am choosing to use appropriately sized pop rivets to secure my battery tubes back into the stock. While the but pad holds the aft end of the battery tubes captive, I think for AWB purposes, a rivet is much more appropriate. This way you have to un-rivet before using additional, but common hand tools to make the stock functional again. Will I test this length of pull before riveting? Probably…
N’JOY!
Let me know what you think. I intend this to be a tutorial of sorts. It makes sense to me because I just did it. That means there is probably some assumptions on my part and inadequacy in my photos that are not obvious to someone that has not done it before. Let me know if you need a hand or clarification and I will try to help as well as improve the post.

This will most likely work for any Magpul stock that uses this type of adjustment mechanism. But I only have the STR. For less complicated stocks, just skip the rivets/frictionlock/battery tube comments and go to work. It might be wise to take additional steps to ensure compliance with AWB requirements in this and all cases. This procedure is theoretical, for reference purposes only, and in no way assumes or provides liability or legal advice.

Time needed, 30-45 minutes to figure it out and complete the project…

TOOLS NEEDED:

Flat head

Drill with assorted bits

Pop rivet squeezer and rivets

AR-15 assembly punches or equivalent

Diagonal cutters or equivalent

Dremel rotary tool with cutting wheel or equivalent

Universal problem solving device

ADDITIONAL MATERIALS NEEDED:

1″ Aluminum rod stock or, you guessed it, equivalent

Little tiny zip lock baggy

First, choose your length of pull adjustment and mark it or just remember where you want it.

Remove the two allen screws holding the but-pad to the stock. Pop the battery storage caps off. With the flat head you can push in the tangs that hold the but pad captive to the back of the stock and set that and its hardware aside. With the battery storage caps removed, you will see a single pop rivet on each side at the aft end of the stock. Drill the rivet out. Choose a drill bit that is just a little larger than the gap in the middle of the rivet. You will see a cylindrical channel running through the middle of the rivet. You want to drill out the wall of that channel without touching the plastic of the stock on the outside of the rivet. Start small on the drill bit, too big and you risk getting into the plastic of the stock.

When you have drilled enough, the little ball-bearing will drop out of the back side of of the rivet. Careful with the drill here so you don’t drill into the nut plate mount for the but-pad attach screws. If the rivet starts spinning with the drill, just wedge that flat head in there to keep it from spinning until you get all the way through. If you picked the right bit and drilled just right, a punch will pry the head of the rivet off the shank and allow you to remove the head of the rivet and discard. For 90% of the time, you will need to use the diagonal cutters (dykes) to bit the head of the rivet off.

Now it gets a little ugly. Due to the but-pad attach screw top nut plate mount’s proximity, you can’t simply push the shank of the rivet through the hole to remove it. Here I used a combo of flat head, punch, drill and universal problem solving tool to mash the hell out of the shank of that rivet to get it out. Just beat it up until you are able to scrape, crush, pry or beg that little bugger out of the stock.

Once the rivets are cleared out, you can remove the entire battery storage tubes completely. In fact, once you get the top half of the rivet out, you can probably get the tubes out of the way so you don’t damage them. They slide aft to disengage from the stock and require no further disassembly to remove. You might consider using the tubes to store hardware and roll pins for later….

With the tubes removed, we can now go to work.

Lets remove the ‘friction lock’. Just tap out that forward roll pin and save for later. Once that pin is out, you need to pry and scrap the friction lock off the stock. Careful here. Try to get two long flat-heads in here. At the aft/long end of the friction lock you will see a little slot in which to slip in a flat head and pry it wider for removal. The roll pin underneath these slots is oversized/long and if you are not careful will gouge the inside of the friction lock pretty heavily. I didn’t see this at first and damaged mine a little so watch out. (in the end the scars are on the inside and it its still functional so don’t stay up late worrying about it Take it easy and use a 3rd hand)

With the fric-lock removed, the oversized/long roll pin holding the length of pull adjustment mechanism plunger captive is ripe for harvest. Careful here, you’ll need that spring some day… and your eyeball. I used a spare punch to block the exit of the spring through the cavity used to install the stock onto the tube. Knock that sucker out and retrieve the hardware from the adjustment mechanism.

Take the spring from inside the adjustment mechanism, get a little zip-lock baggy, drip a bunch of gun oil and seal it inside for later. Much later…

Now, get your dremel and aluminum rod. Cut a piece that is roughly 3/4″ inch long. Go a little long here. The reason I like aluminum not steel, is the ease of working with it. Cut and shave the rod to fit into the adjustment mechanism where the spring used to reside.

View attachment 41164View attachment 41165

As you shave the rod down, keep test fitting the rod into the adjustment mechanism. Remember, the spring is removed and does not go back into the stock. Keep in mind, when test fitting the length of the aluminum rod, there is a channel in the cross rod on the adjustment mechanism. To get the tightest fit, apply some pressure to the bottom of your aluminum rod to ensure that the cross bar is oriented properly. Otherwise, your rod will be too long/short when final assembly time comes.

This part is really up to you. How much wiggle do you want in the adjustment lever? If you don’t care or aren’t picky, just cut a piece that keeps the plunger from disengaging from the buffer tube and you are ready for assembly. I didn’t want any wiggle, so I shaved it down so that the oversize/long roll pin didn’t quite fit back into the adjustment mechanism. Then I used the universal problem solver against the side of my punches to compress a channel into the face of the bar stock for the roll pin to fit into. This made the lock up completely immobile, no wiggle or give when the adjustment lever is pressed.

View attachment 41166View attachment 41167

Now, I won’t bore you with the reassembly procedure because it is just the reverse of what we just did.

REMEMBER: THE SPRING DOES NOT GO BACK INTO THE ADJUSTMENT MECHANISM/PLUNGER!!! If you cut your aluminum rod to accomodate the spring as well, you are probably wrong, and probably won’t get the thing back together again… But feel free to attempt it

View attachment 41170

Now, I am choosing to use appropriately sized pop rivets to secure my battery tubes back into the stock. While the but pad holds the aft end of the battery tubes captive, I think for AWB purposes, a rivet is much more appropriate. This way you have to un-rivet before using additional, but common hand tools to make the stock functional again. Will I test this length of pull before riveting? Probably…

N’JOY!

Let me know what you think. I intend this to be a tutorial of sorts. It makes sense to me because I just did it. That means there is probably some assumptions on my part and inadequacy in my photos that are not obvious to someone that has not done it before. Let me know if you need a hand or clarification and I will try to help as well as improve the post.

Last edited: