Modstock Installation and Operation ManualUpdated: September, 2009

Congratulations on the purchase of your VLTORModular Firearm Buttstock, (a.k.a. Modstock). Wehope you will appreciate the quality construction andversatility the Modstock offers. Please read thisInstallation and Operation Manual thoroughly beforehandling the Modstock and/or the contents of thebox.

WARNING: The Installation of a Vltor Modstock Systemshould be performed by a qualified gunsmith orqualified United States Military small arms technician.Refer to the current United States Military TechnicalManuals or Colt factory technical manuals for propertool needs and torque specifications.

LEGAL NOTE: The Vltor Modstock can be used on allAR-15/M16/M4 Rifle or Carbine systems. Vltorrecommends the installer and/or the firearm’s ownercheck with local, state and federal law beforeinstalling or possessing any product manufactured orsold by Vltor, as Vltor is not responsible for theinstallation or use of any Modstock system, or anyother related Vltor product.

Important Note Regarding Military Specification(MilSpec) dimensioned carbine receiver extensions:The Vltor Modstock System will fit only militarydimensioned (MilSpec) receiver extensions. Othermakers’ collapsible stock receiver extensions may notfit properly or at all.

WWW.VLTOR.COMIf you encounter any difficulties operating theModstock system, or if your qualifiedgunsmith/technician has questions regardinginstallation of the Modstock system, feel free tocontact Vltor Service Department.

telephone: (520) 408-1944email: service@vltor.com

Colt is a registered trademark of Colt’s Manufacturing Company, Inc.

Go To WWW.VLTOR.COM For The Following:

• Operation and Installation Manual.• New Products and Accessories.• Frequently Asked Questions ( FAQ ).• VLTOR News and Related Links.

VLTOR WEAPON SYSTEMS3735 N. Romero Rd.Tucson, AZ 85705 USA

The Modstock system and related Vltorcomponents are Patent Pending

VWS-M002 RevA, Sep 2009

Installation of the Rifle Modstock on a CollapsibleButtstock Receiver Extension

Removal of existing collapsible buttstock andinstallation of new Modstock - To remove theexisting collapsible buttstock, grasp the entirelocking lever assembly and pull it away from thestock (to fully retract/disengage the lever lock pin)while simultaneously sliding the stock to the rear ofthe receiver extension. This may be betteraccomplished by having another person hold the rifle,while you grasp the stock in one hand and theadjustment lever in the other, and pull the two apart.To install the new collapsible Modstock assembly,reverse the removal process. See Figure 1.

STOP!READ THIS FIRST

Improper installation can result in damage. Do notattempt installation if you are not familiar with thefirearm, tools and techniques mentioned. You areresponsible for any damage or injury resulting fromthe improper use or installation of this product.

complete locking position, simultaneously forcingthe Manual Lock-Pin upward in the receiverextension slot. To unlock and remove the ManualLock-Pin, reverse the installation process.

Installation of Cheekweld Adapteror Modstock Accessory Compartment

Note: Basic Carbine Kits (ACB and ACBK) are onlyequipped with Accessory Compartments.

The installation of the Cheek Plate and AccessoryCompartment is similar. Both items feature lockingfingers on the upper portion and mounting flange atthe base.

To install, first insert the locking fingers into thesquare mating holes along Modstock’s body, thenpivot the accessory downward until the accessory’smounting flange contacts squarely against thesurface of the stock. On the Carbine Modstock, theinstaller may need to retract the Lever Lock PinPaddle to give access.

Modstock kits come equipped with two AccessoryNuts and two Accessory Mounting Screws. BasicCarbine Kits (ACB and ACBK) are equipped with onlyone Accessory Nut and one Accessory MountingScrew. To install, index and insert the Accessory Nutinto the accessory and through the Modstockmounting I-beam. After insertion of the AccessoryNuts, install the Accessory Mounting Screw on the

opposite side of the Accessory Nut’s insertion. Threadthe Accessory Mounting Screw(s) to a snug fit with theaid of a 3/32 hex wrench (which is provided with theModstock kit). The combination of the AccessoryMounting Screw and Nut will sandwich theAdapter/Compartment and the Modstock together.

Compartment Cap Installation Tip: Some may find theinstallation and removal of the caps to be difficult. Toaid in the process, apply a dab of petroleum gel orsilicon grease to the rubberized material, which sealsto the inside of the compartment.

The Operation of the Quick Detach Sling Swivel

Note: Basic Carbine Kits (ACB and ACBK) are notequipped with the QD Sling Swivel.

The Vltor Modstock system has the ability to mount asling, both conventionally and by quick detachablemeans. To allow the sling to be quick detachable,Vltor has equipped most Modstock kits with one QuickDetachable Sling Swivel.

To install the QD sling swivel into the Modstock, firstinsert the body of the sling swivel into the SlingSwivel Locking Sleeve located within the Modstock.With the Sling Swivel partially installed, complete theinsertion by applying pressure to the push-button.The button is located on the exposed portion of thesling swivel’s body. By pressing the button, theswivel’s ball bearings will retract, allowing the totalinsertion of the sling swivel into the Sling SwivelLocking Sleeve. To remove the QD sling swivel simplyreverse the installation process.

The Modstock has multiple mounting points for a QDSling Swivel. For every one Sling Swivel LockingSleeve molded in a Modstock, the QD Sling Swivel canmount ambidextrously to either side. For example,the rifle Modstock has two Sling Swivel LockingSleeves giving the operator the choice of fourmounting possibilities. The collapsible Modstock onlyfeatures one Sling Swivel Locking Sleeve, which givesthe operator the choice to mount the sling fromeither side of the stock.

AR Rifle Series

Legal note: Refer to Legal Note/Disclaimer at thebeginning of the manual, as many states &municipalities consider this to still be a “collapsiblestock”.

Removal of existing buttstock / installation of RifleModstock - Remove the large slotted screw from rearof the existing fixed buttstock, taking care not to losethe takedown spring & detent from the rear of thelower receiver. If removing an “A2” length buttstock,save the buttstock screw and 5/8” spacer from rearof tube for future use.

Install the rifle Modstock over the receiver extension,insuring that the indexing nub on the forward portionof the stock is flush within the receiver, and that thetakedown detent & spring are properly installed inthe receiver.

For “A1” length (ARM-1 series) Modstocks, with theButt Cap in place, install the new A1 length Butt CapScrew (included). Tighten screw to properspecification as required in the United States militaryor Colt factory technical manual.

“A2” length (ARM-2 series) Modstocks install the sameway, except using a longer stock screw and 5/8”spacer (not included) between the receiver extensiontube and Modstock Butt Cap.

Installation of the Rifle Modstock to theCollapsible Buttstock Receiver Extension

A Manual Lock-Pin must be installed to lock the stockinto position. The Manual Lock-Pin is equipped withevery rifle Modstock kit and consists of a steelindexing pin and a pivoting composite material latch.To lock in position, install the Lock-Pin into the accessport, inserting the pin into the receiver extension’sadjustment slot (see figure 2). With the pin installed,rotate the Manual Lock-Pin’s Locking Latch until itcontacts the ramping surface (the bridge of materialalong the mounting beam). By applying pressure tothe Locking Latch, it will ramp-up and rotate to a