UTG AR-15 A2 Fixed Buttstock Complete Assembly

UTG AR-15 A2 Fixed Buttstock Complete Assembly UTG Black Storage Compartment

UTG AR-15 A2 Fixed Buttstock Complete Assembly UTG Black Storage Compartment

Note:

All component terms used in this write-up are terms used in the Disassembly Views of Bushmaster XM15 E2S Rifle, which I have included at the end of the article. Since I could not find an IPB (Illustrated Parts Breakdown) specific to the “SRC”, this one will suffice for general component identification.

For the most part (and there may be exceptions), the collapsible stocks that are usually mounted on new AR15 MSRs are made for the masses and different size operators. I prefer a solid stock, full or carbine length. Thus, when the opportunity presented itself to personalize my Windham Weaponry “SRC”, the stock was the first to go. Well, the third to go after installing a good optic and a good set of Magpul steel flip sights.

The UTG A2 fixed stock is a rifle-length fixed stock that is slightly shorter than the collapsible stock (that came with the WW “SRC”) when fully extended, but slightly longer than the A1 stock that is more in proportion to carbine-length MSRs.

The UTG A2 fixed stock is molded from an advanced impact resistant polymer and includes a storage compartment so that you can conveniently store your cleaning kit or replacement parts, a 4.8 ounce Buffer Assembly, Action Spring (a.k.a., buffer spring), Receiver Extension, Buttcap Spacer and Buttplate Screw. My particular stock is black but other colors are available.

The Product Box

The Product Box

The Product Bag

The Product Bag

The Product - Everything Necessary For Installation

The Product – Everything Necessary For Installation

The UTG A2 fixed stock is shipped within plastic and within a cardboard box.

All the inner parts are installed in the stock and held in place by an end cap that includes a cautionary label; “Spring and Buffer are compressed inside. Please point the cap downward and open with great caution to avoid any sudden spring release.” Believe me that they mean it.

Now, to be clear, this was not my first rodeo with the UTG A2 stock and the Windham Weaponry “SRC” has a similar stock had been mounted on a previous occasion. Much to my chagrin, the earlier stock was a dark grey that I did not think fit in with the looks of the firearm after it was mounted. I made a decision was made to change out the stock with a black one and use the innards that came with the new stock for a Magpul AR-15 MOE Rifle Stock Polymer Black MAG404-BLK that is going to be mounted on the Ruger AR 556.

Textured Buttplate With Storage Access

Textured Buttplate With Storage Access

Enough Storage for Quite A Few Slim-Jim Snacks and Other Essentials

Enough Storage for Quite A Few Slim-Jim Snacks and Other Essentials

The UTG A2 fixed stock is nicely textured and also incorporates the “trap-door” storage area as does all UTG A2 stocks. The butt pad is nicely fitted to the stock and incorporates diamond checkering for a firm hold when pressed against the shoulder. The trap door and latch feels sold are also made of polymer material. The buttstock also incorporates a sling mount that is held into place by the Rear Swivel Screw.

While no showpiece, this A2 stock assembly augments the looks of the Windham Weaponry “SRC” and is highly functional for me.

Total unit weight is 25 ounces.

The stock is manufactured in Taiwan and should feel right at home when Wolf Gold .223, 55-grain, FMJ ammunition (also made in Taiwan) is being thrust out of the muzzle.

This would normally end the review for me, but I wanted to share information about replacing your collapsible stock with this one, some ways to make it better, and a few areas that you need to be concerned with during the swap-out from one stock to another. If this interest you, please read further.

REMOVAL AND REPLACEMENT:

If you are not confident in replacing the collapsible stock with the A2 stock, seek out a certified gunsmith to perform the work for you. However, if you are confident that you can replace the collapsible stock with the A2 stock, continue reading for directions to do so.

Tools:

The tools that you will need to remove the collapsible stock and install the A2 stock follow:

  • An AR wrench (to remove the Receiver Extension Locking Nut, to remove the existing stock, and install the “rifle” length tube needed for the A2 stock) or have a friend that has one and is willing to help you (as I did).
  • If you do not have an AR tool, an adjustable wrench or a 5/8-inch open end wrench.
  • A quality, hollow-ground flat-tip screwdriver to fit the Buttplate Screw. Note: I highly recommend the Weaver Multi-Bit Tool Kit. If you have this kit, the Leupold Hex Bit (#203) is a perfect fit for the Buttplate Screw.
  • Patience

#AllSpringsMatter

#AllSpringsMatter

#AllSpringsMatter is the hashtag for the day when attempting to replace your existing stock with this one. Two springs are particularly susceptible to flying to locations unknown by modern man; the Takedown Pin Spring and the Buffer Retainer Spring. The latter can be found rocketing skyward (along with the Buffer Retainer) if not restrained and the former can be easily damaged (as I found out with the first outing with this stock). Wear eye protection!

NOTE TO READER:

Since including images really messes up instructional steps, I have included reference images at the end of the article.

Removing the Collapsible Stock:

Safety First – Always! To begin the swap out, the firearm needs to be safety checked for existing installed ammunition. In other words, unload and safe the weapon.

  1. Separate the upper from the lower and set the upper aside; you will not need it for the remainder of this disassembly.
  2. Re-orient the lower as needed to access the Buffer Assembly. Caution! The Buffer Assembly is under spring tension. Press down on the Buffer Retainer while holding the Buffer Assembly in place.
  3. Slowly slide the Buffer Assembly out from the Receiver Extension.
  4. Slightly loosen the Receiver Extension Castle Nut with the AR Wrench.
  5. Hold the lower upright (butt in the air). Place a finger across the End Plate. This plate holds in the Takedown Pin Spring and Takedown Pin Detent in place. We want the End Plate to remain holding the Takedown Pin Spring while unscrewing the Receiver Extension Castle Nut. The End Plate must be removed straight back to the rear lest you bend this spring.
  6. While holding the End Plate in place, slowly unscrew the Receiver Extension Castle Nut completely.
  7. With the finger holding the End Plate, allow the End Plate to move rearward. Ensure that you do not allow the End Plate to twist; this movement could damage the Takedown Pin Spring.
  8. Once the Takedown Pin Spring’s tension has released, remove the Takedown Pin Spring and set it aside for use with the A2 stock. (Note: I like using magnetic trays for holding parts like these; they are available at most auto parts stores or Harbor Freight.) Note: At this time, there is no spring tension applied to either the Rear Takedown Pin or to the Takedown Pin Detent. Care must be taken to prevent these parts from falling out. On the other hand, you can remove these parts and set them aside for use when assembling the new A2 stock. Note the orientation of these parts upon removal to ensure that they are properly installed during assembly of the new stock.
  9. CAUTION! The Buffer Retainer is under spring tension. Press the Buffer Retainer down until it just clears the Receiver Extension (a.k.a. Buffer Tube). While holding the Buffer Retainer down, slowly unscrew the buffer tube just enough to clear the Buffer Retainer.
  10. Slowly release the Buffer Retainer and Buffer Retainer spring until spring tension is released.
  11. Remove the Buffer Retainer and Buffer Retainer spring. Set aside for future assembly.
  12. Completely unscrew the Receiver Extension from the lower (which also includes the collapsible stock).
  13. Optional Step: At this point, I like to apply a thin coat of Lubriplate 130-A to the Takedown Pin and also to the Takedown Pin Detent.

This completes the removal of the expandable stock from the MSR.

Installing the UTG A2 Stock:

Before I get to the instructions for installing the A2 stock, I would like to interject some information regarding how to make the A2 stock relatively rattle-free.

One of the many complaints about this stock is that it rattles. The rattle is primarily caused by excessive play of the Buttstock Spacer. Another mention is the Action Spring “sproing”, which is caused by the Action Spring contacting the side of the Receiver Extension. The Action Spring does sing, but it sings a welcome tune. Also, the rear compartment latch is a little noisy, being plastic and not being tight with the Buttplate. A ½-inch butt pad (like a Limbsaver) takes care of that and makes up for the LOP lost by converting to the A2 stock. Besides, the latch noise goes away when you shoulder the firearm.

Let’s look at the rattle caused by the Buttstock Spacer.

The distance from the rear internal detent for the spacer, to the front of the stock, is approximately 10.25 inches. The length of the receiver extension, including the buttcap spacer, is 10 inches. In other words, there is .25 inches of play between the end of the spacer and the buttplate. This is the reason that these types of stocks rattle. What is needed is a spacer(s) that will fill the ¼-inch gap, but allow some compression so that the stock properly seats against the lower.

While I can’t guarantee a rattle free stock (I can’t do anything about the buffer tube and spring, nor for the rear storage latch), I can guarantee that the rattling will not be caused by the buttstock spacer. To eliminate any movement from the stock on the lower, and rattles caused by a loose buttstock spacer, takes three o-rings commonly found at auto parts stores, Lowes, or harbor Freight. The o-rings provided the necessary spacers while providing a soft compression and a tight stock to lower mating.

In the indent of the lower, where the stock mates, insert a 012/P9 o-ring.  Note the hole for the Takedown Pin Spring

In the indent of the lower, where the stock mates, insert a 012/P9 o-ring. Note the hole for the Takedown Pin Spring

In the indent of the lower, where the stock mates, insert a 012/P9 o-ring. This o-ring prevents movement between the stock and the lower

At the tightening lug of the receiver extension, install a 113/P14 o-ring.

At the tightening lug of the receiver extension, install a 113/P14 o-ring.

This o-ring provides a spacer.

At the end of the Buttcap Spacer, install a 115/P18 0-ring.

At the end of the Buttcap Spacer, install a 115/P18 0-ring.

At the end of the Buttcap Spacer, install a 115/P18 0-ring. This o-ring butts against the Buttstock well where it receives the Buttstock Spacer.

When the stock is tightened against the lower, the o-rings provide a cushion to prevent stock movement and quiet an otherwise loose and noisy Buttstock Spacer.

At this time, you may want to apply a dab of blue thread-locker to the upper buttplate screw. This will help to prevent the top Buttplate Screw from backing out during recoil, but allows for easy removal of the screw if necessary.

So, let’s get started with the installation of the UTG AR-15 A2 Fixed Buttstock Complete Assembly.

  1. Perform a test fit of the Receiver Extension to the lower.
  2. Install the Buffer Retainer and Buffer Retainer Spring.
  3. (R1) Check the clearance of the Receiver Extension and the Buffer Retainer. The receiver extension should hold the Buffer Retainer in place and allow up and down movement. If the Receiver Extension places a bind on the Buffer Retainer, with the Receiver Extension tightened, some very minor filing of the Receiver Extension with a fine round file may be required to achieve the proper clearance. Use a scribe or marking device to mark the point where the Receiver Extension meets the Buffer Retainer. Press the Buffer Retainer down and remove the Receiver extension. Ensure that the Buffer Retainer does not fly out of the lower. Perform minor filing and test fit as explained previously.
  4. Once the Receiver Extension to Buffer Retainer is correct, install the Receiver Extension and tighten it with the AR wrench, adjustable wrench, or a 5/8-inch open-end wrench. DO NOT OVERTIGHTEN!
  5. Hold the lower with the rear of the lower upward and install the Takedown Pin (if removed). Note that the slot in the Takedown Pin faces the rear of the lower.
  6. Install the Takedown Pin Detent into the rear of the receiver. Note that there is no wrong way to install the Takedown Pin Detent.
  7. (R6) Install the Takedown Pin Spring.
  8. Install the Buttcap Spacer on to the Receiver Extension.
  9. Slide the A2 buttstock over the Receiver Extension. There is a detent in the lower in which the protrusion on the front of the buttstock mates. Prior to engaging the Takedown Pin Spring with the front of the buttstock, align the buttstock so that protrusion and the detent match. Slowly push the buttstock straight down, compressing the takedown pin spring evenly, until the buttstock is properly seated. Note: If you bend the takedown pin spring, it must be replaced. I would advise that you purchase a spring kit for your AR before attempting to replace the stock, so that a spare takedown pin spring is available – just in case. Trust me, I know about these things and about this spring (mine was damaged the first time around).
  10. While keeping constant pressure on the stock against the lower, install and tighten the top Buttplate Screw. Note: Use of a hollow-ground flat tip screw driver of the appropriate bit size will prevent damage to the screw is highly recommended.
  11. Install the Action Spring and Buffer Assembly into the Receiver Extension.

This completes assembly of the A2 stock to the MSR.

If you opted to install the o-rings, the stock will be as rattle-free as it can be.

UTG A2 Stock Fully Assembled, Slung, and Ready To Go

UTG A2 Stock Fully Assembled, Slung, and Ready To Go

Install the lower to the upper and you should be good to go. Enjoy your new rifle-length A2 stock.

SUMMARY:

If you prefer fixed stock over collapsible stocks, the AR-15 A2 Fixed Buttstock Complete Assembly UTG Black Storage Compartment is a good choice. Note that the UTG A2 stock comes in different lengths: the rifle stock (what this article is about), a carbine stock (a shorter Receiver Extension, Action Spring, and Buffer Assembly. The Buttcap Spacer is not needed), and a compact A2 stock (very short).

The beauty of installing the A2 “rifle-length” stock is that if you decide to install a Magpul or other that uses the “rifle-length” Receiver Extension, it is a quick and easy swap out. I plan on installing a Magpul AR-15 MOE Rifle Stock Polymer Black MAG404-BLK on the Ruger AR 556, and I can use the parts contained in this kit for that installation.

PICTORIAL REFERENCES:

Takedown Pin Spring

Takedown Pin Spring

Takedown Pin Detent

Takedown Pin Detent

Takedown Pin

Takedown Pin

Buffer Retainer Spring

Buffer Retainer Spring

Buffer Retainer

Buffer Retainer

Hold the Receiver Extension End Plate While Unscrewing the Castle Nut to Prevent Damage to the Takedown Pin Spring

Hold the Receiver Extension End Plate While Unscrewing the Castle Nut to Prevent Damage to the Takedown Pin Spring

Press the Buffer Retainer Down While Unscrewing the Receiver Extension To Prevent Loss of the Buffer Retainer and Buffer Retainer Spring

Press the Buffer Retainer Down While Unscrewing the Receiver Extension To Prevent Loss of the Buffer Retainer and Buffer Retainer Spring

(R1) The Buffer Retainer and Spring is Held Captive by the Receiver Extension

(R1) The Buffer Retainer and Spring is Held Captive by the Receiver Extension

Use Caution when Assembling the Stock to the Lower - Do not Damage the Takedown Pin Spring!!

Use Caution when Assembling the Stock to the Lower – Do not Damage the Takedown Pin Spring!!

ADDITIONAL REFERENCES:

UTG AR-15 A2 Fixed Buttstock Complete Assembly UTG Black Storage Compartment: http://www.cheaperthandirt.com/product/ARR-205?td_source=search

Source for O-rings: Storehouse 397 piece O-ring Assortment, Harbor Freight

ERGO Grip AR-15 Lower Receiver Spring Replacement Kit 9 Piece 4612: http://www.cheaperthandirt.com/product/9-105458?td_source=search

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About Taurian

Taurian is a U.S. Army veteran and former LEO and Defensive Tactics Instructor. Taurian also has over fifty years of experience as a Technical Writer and Training Program Developer. After leaving home at the age of ten without any shoes, Taurian continues on with many years devoted to the keeping and bearing of arms.

One Response to UTG AR-15 A2 Fixed Buttstock Complete Assembly

  1. Pingback: Magpul AR-15 MOE Rifle Stock Polymer Black MAG404-BLK | Gun Toters

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