How to pin a Magpul ACS Stock

beaker

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Living in MA, we need to pin an adjustable stock so it can't be moved. I pinned my Magpul ACS stock and it seems to work just fine so given the lack of instructions I found I figured I'd share how I did it. This will work for a Magpul CTR stock, and probably a MOE, but I don't have a MOE to look at.

ADDED PICS OF CTR STOCK PINNED THE SAME WAY. Sorry!

It is surprisingly easy to do! Do this at your own risk!

What you need to do this:

You will need some blue (removable) loctite to re-assemble the butt pad, small tubes are available in auto parts stores or Home Depot etc.

A roll pin. 1/8 or smaller and the right size drill. I used a 1/8" (0.132 - 0.134") roll pin for a trigger guard that I didn't use for building this rifle. Home Depot or Lowes has roll pins.

A SHARP Drill appropriate for the Roll Pin Diameter (I used a 1/8 Drill)

A roll pin punch for the roll pin you are using (I used a 1/8 Roll Pin Punch)

Hammer

Hand Drill or Drill Press (preferred) - I used a hand drill, but my nickname used to be "Human Drill Press" [wink] YMMV!

INSTRUCTIONS:

Adjust the stock to your preferred (FINAL) location.

First you have to remove the butt pad using an allen wrench. Put pieces aside.

Then pull out the end caps for the storage tubes and let them hang.

Slide the storage tubes all the way back towards the butt pad.

IMG_6102_resize.JPG


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Use a large flat head screwdriver to gently pry the tubes off of the stock, pry from around the release lever area. They should pop right out.

IMG_6104_resize.JPG


Remove both storage tubes the same way and put them aside.

It looks to me that the best place to put the pin is right between the locking lever and the release lever.

IMG_6105_resize.JPG


Drill your hole right at the top/middle of the flat area so you catch both sides of the stock and the buffer tube rail. It should look like this:

IMG_6106_resize.JPG


Place your roll pin into the hole and drive it in using the appropriate roll pin punch.

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Drive the pin flush with the side of the stock.
IMG_6110_resize.JPG


Put the storage tubes back in and slide them back into the locking grooves. I used the corner of the bench on the bottom and pushed down on the stock.

Put the butt pad back on and reassemble with screws. Be sure to put some blue loctite on the screws or they will come out again.

IMG_6111_resize.JPG


Afterwards, you can't tell it's been pinned (other than you can no longer move the stock).

IMG_6112_resize.JPG


All back together, pinned and MA compliant! [grin] [sad2]

IMG_6114_resize.JPG


I have another rifle with a Magpul CTR stock (This is a fantastic stock) that I pinned the same way. Here are some shots of the pinned Magpul CTR stock using the same 1/8" trigger guard roll pin from an LPK. You can get 1/8 roll pins at Lowes or Home Depot.

IMG_6392_resize.JPG


IMG_6391_resize.JPG


Here is the Delaware lower with TacSol 22 upper with all magpul furniture. I like.
IMG_6395_resize.JPG
 
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drgrant

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Nice job... at least it won't be that hard to undo when you escape MA (or you can "reassign" the stock to a preban lower).

-Mike
 

beaker

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Yea, it is definately easy to undo if the state gov comes to its senses about these moronic AWB laws. They haven't helped anything.

Nice job... at least it won't be that hard to undo when you escape MA (or you can "reassign" the stock to a preban lower).

-Mike
 

beaker

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Lol, sorry man! I'm just trying to survive. And people do ask how to pretty often so ...

I'm over it now...Nice job, as people are asking how to pin a collapsable stock from time to time. Okay, I'm not over it...Sorry...I need a hug...[crying]
 
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Asesome job and a great how-to. I'm just glad I don't have to worry about it living in New Hampshire.


Yup, a stock that can be adjusted for length of pull for different shooters or different levels of clothing is definately an "EVIL" military only feature that has "no civilian use"

Don't you wear exactly the same jacket everytime you shoot or hunt?
 
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good stuff, i'm from ct and we cant have these "Evil" stocks either..

question though, does that "extension" between the rifle and the stock have to be there? the only reason why i have been looking for a new stock is to shave about 1.5 - 2.5 inches from my rifle's overall length (still would be within legal length) so it is more comfortable for me to fire and easier to acquire the target down range.

thanks.
 

beaker

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You mean the buffer tube? If so, then yes, you need it since that is where the buffer spring and buffer go. If I am misunderstanding what you mean, please post again! You can move the stock up close to the lower receiver then pin it, it is adjustable until then. You just have to maintain the minimum overall length of the rifle.

good stuff, i'm from ct and we cant have these "Evil" stocks either..

question though, does that "extension" between the rifle and the stock have to be there? the only reason why i have been looking for a new stock is to shave about 1.5 - 2.5 inches from my rifle's overall length (still would be within legal length) so it is more comfortable for me to fire and easier to acquire the target down range.

thanks.
 
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Must you pin the stock thru the buffer tube? Is that a legal issue or just the easiest place? What if you pinned the release lever so that you can't pull up on the lever?
 
W

wolf223

Must you pin the stock thru the buffer tube? Is that a legal issue or just the easiest place? What if you pinned the release lever so that you can't pull up on the lever?

here is what ONE of my evil brothesr would say:

unless your knocking off banks, who the eF cares? but he's crazy. he has all kinds of non-compliant stuff.

he's also a cop though. [laugh]

me? i wear rubbers
 
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Must you pin the stock thru the buffer tube? Is that a legal issue or just the easiest place? What if you pinned the release lever so that you can't pull up on the lever?

That probably wouldn't be nearly as easy as the way the OP did it.

As long as the stock is fixed, you're good to go.



joeg, except in the forward most position, all collapsible stocks will have some receiver extension exposed. It's just the nature of the beast. if you're looking for a fixed stock with a shorter LOP, you can get skeleton stocks (ACE) and entry-length A2-style buttstocks. Both are fixed by virtue of design, rather than modification.

The MagPul UBR also doesnt show any receiver extension, even when its all the way out. I'm not sure how you would pin the UBR, though.
 
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This may be a dumb question, but can you take it to the range to test fire it before pinning? Seems like the only way to know the "best" position would be to actually try it in more than one. How does that situation work? I am still researching, but planning my first AR build sometime this winter, and trying to figure out the details on all of these evil, babykilling accessories.[wink]
 
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I don't believe there is any provision in the AWB that allows you to bring a non-compliant firearm to the range to test fire it before bringing it into compliance. Then again, I've never seen any Pinned Stock Compliance Officers any time I've been at the range either...
 
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This may be a dumb question, but can you take it to the range to test fire it before pinning? Seems like the only way to know the "best" position would be to actually try it in more than one. How does that situation work? I am still researching, but planning my first AR build sometime this winter, and trying to figure out the details on all of these evil, babykilling accessories.[wink]

Sure can... Just call the ATF before you go and they will give you permission.
 
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Pinning CTR stock

Would I need to replace the buffer tube if the weapon has a typical Bushmaster MA-compliant buffer tube?

Meaning the tube itself has no rail/adjustment holes like an adjustable stock would. I would love to get a CTR on there to even out the other Magpul furniture.
 

beaker

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You would have to change the buffer tube, buffer and buffer spring to use a Magpul adjustable stock. I am assuming you have an A1 or A2 stock.


Would I need to replace the buffer tube if the weapon has a typical Bushmaster MA-compliant buffer tube?

Meaning the tube itself has no rail/adjustment holes like an adjustable stock would. I would love to get a CTR on there to even out the other Magpul furniture.



Sent from my Droid using Tapatalk
 

Stroeman

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Thanks great info, just finished mine. Just a note it appears Magpul has added a 3/32 roll pin to the butt end of each tube. I used a 3/32 bit in my drill press and it lifted them right out, and I just replaced them at the end. They can't be pushed through they bottom against the upper metal rod in the stock.
Just thought I'd let everyone know
 
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