ARMALITE AR-10 A4 UPGRADE PROJECT-ARMALITE AR-10A4CF SEMI AUTO CARBINE

MY ARMALITE AR-10 A4 UPGRADE | AR-10A4CF

My Armalite AR-10A4CF was purchased back in 2012 in the months following the Sandy Hook massacre. That was a time when anything assault rifle related was impossible to buy. I also recognized that there was a good chance my home state would use the tragedy to impose more restrictions. I was not wrong. If I wanted to own an Armalite AR-10 I would need nothing short of a miracle. Fortunately that miracle presented itself in the form of Armalite’s former marketing director Arthur Steadman. Under Armalite’s previous ownership we had a fantastic working relationship from shortly after the launch of this site until Armalite sold to Strategic Arms Corp.  Anyhow I quick message to Arthur explaining my plight and he was on the case. A few days later I had an Armalite AR-10 A4 inbound, more specifically the AR-10A4CF. Naturally this was mostly great news.

ARMALITE AR-10A4CF SEMI AUTO CARBINE-ARMALITE AR-10 A4 Upgrade Project

ARMALITE AR-10 A4 Upgrade Ready

Unfortunately though beggars could not be choosers. I was not able to chose the AR-10 model I was getting. I had to settle on the AR-10A4FC. It was a demo booth rifle from SHOT Show. It was Armalite green and used Armalite magazines. I had hoped for a rifle that would accept the Magpul 308 PMAGS and anything other than green. This brings us to the point of this page, my AR-10 A4 Upgrade.

 

EASY DROP-IN ARMALITE AR-10 A4 UPGRADES

The other day we received an email from a reader “Michael”. Michael owns an Armalite DEF-10. The Armalite DEF-10 is an “A” series AR-10 that is nearly the same rifle as my AR-10A4CF. The major difference is the DEF-10 accepts the Magpul 308 PMAGS I mentioned previously while AR-10 uses the proprietary Armalite magazines. The DEF-10 also has a single stage trigger while my AR-10 AP4 has a two stage. Michael asked what can be done with his “Plane Jane” DEF-10. It occurred to me until now there was never a write up of my rifle on this site. Below is my rationale and parts choices for my AR-10 A4 Upgrades

AR-10 A4 UPGRADE – WHAT STAYED

When evaluating the AR-10A4 carbine as it shipped from Armalite it quickly became apparent that it is actually a very good rifle for it’s intended purposes and buyers. The rifle barrel and trigger stayed. The barrel and trigger combination for my purposes are sufficient. The rifle is not meant for long range competition. It is accurate enough for medium range hunting, tactical and defensive situations.

AR-10 A4 UPGRADE – WHAT’S REPLACED

Typically a firearms appearance doesn’t mean much to me. As I have stated many times on this site “Form must follow function”. I can appreciate a good looking weapon. I just wont base a hardware selection on appearances alone. That said I despise the green Armalite furniture especially the A2 handguard. Translation, rifle stock, pistol grip and handguard had to go. Beyond that I am left handed and  a huge proponent of the Battle Arms Development Ambidextrous Safeties. The factory safety was replaced.

 

MAGPUL ACS-L STOCK FLAT DARK EARTH-AR-10 A4 Upgrade

MAGPUL ACS-L STOCK SPECIFICATIONS-MILSPEC

ACS-L Carbine Stock, Mil-Spec

  • Weight: 12.5 oz.
  • Weight, w/receiver extension: 16.5 oz.
  • Length, max: 8.0 in.
  • Width, max: 2.2 in.
  • LOP Adjustment Range: 3.3 in.
  • LOP, M4 Collapsed: ~11.6 in.
  • LOP, M4 Extended: ~14.9 in.

* Friction lock performance may vary depending on the host receiver extension’s dimensional tolerances.

** Specifications based on standard-length (flat-back) M4 Carbine Receiver Extension and may vary depending on tube manufacturer.

 

MAGPUL ACS-L STOCK MILSPEC FLAT DARK EARTH

MAGPUL ACS-L STOCK FLAT DARK EARTH

The factory stock on the AR-10 AP4 was I believe an inexpensive BCM stock. I was pretty eager to replace it. The Magpul ACS-L was an easy decision. The Magpul ACS is already one of my favorite stocks. The “L” is a new variant of the ACS. The ACS-L lighter and slimmer because the battery storage is omitted.

Swapping one collapsible stock with another typically takes seconds. Easy AR-10 A4 Upgrade!

The Magpul ACS-L (Adaptable Carbine Stock – Light) is a drop-in replacement buttstock for AR15/M4 carbines using commercial-spec sized receiver extension tubes. A streamlined version of the ACS, the ACS-L utilizes the same center storage compartment and cheek weld but removes the battery tubes for a slimmer, lighter weight package. Made in U.S.A.

MAGPUL ACS-L FEATURES

  • Mounts on commercial-spec sized carbine receiver extension tube (not included) from manufacturers such as Bushmaster, DPMS, Olympic, and others (please see the note below)
  • Sloping cheek weld provides a wide contact surface for user comfort
  • Storage compartment in tail of stock with positive latching access door on right hand side
  • Supplemental friction lock minimizes accuracy robbing wobble*
  • Shielded release latch prevents snagging and accidental operation
  • Premium chrome-silicon lock spring provides positive locking and long service life
  • Replaceable 0.30″ Rubber Butt-Pad offers an anti-slip surface and increases impact protection
  • Compatible with Magpul ASAP®, ASAP® QD, and other receiver-mount sling attachments
  • Sling Mounts
    • Mid – Included reversible Sling Mount Kit – TYPE 3 fits up to 1.5″ push-button swivels (swivel not included)
    • Rear/Bottom – 1.00″ sling loop

MAGPUL MOE K2+ GRIP FDE

The Magpul MOE is my “go to” pistol grip. I went with the MAGPUL MOE K2+ GRIP as it was a brand new product at the time of purchasing my AR-10 AP4.

A pistol grip is a very easy upgrade but be sure to follow the instructions so you don’t lose the spring and detent pin held captive by the grip.

The MAGPUL MOE-K2+ Grip combines reinforced polymer body construction with comfortable, wrap-around rubber overmolding for maximum weapon control in adverse environments. Similar in concept to the smaller MOE-K, the MOE-K2 is a drop in upgrade for AR15/M4’s that offers a more vertical grip angle, but in a full-size grip design. The steeper vertical grip angle is optimized for use on PDW (Personal Defense Weapon) configurations and improves comfort and control on short LOP rifles that bring the primary hand in closer to the shooter’s body. With the rubber overmolding for positive weapon control, compatibility with optional Storage Cores for gear stowage, and a unique backstrap design for proper trigger finger placement, the K2+ brings modern styling, ergonomics, and comfort to the AR platform. All mounting hardware and a basic grip cap included.

MAGPUL MOE K2+ GRIP SPECIFICATIONS

  • MOE-K2+ Grip
    • Weight, w/hardware: 3.1 oz.
    • Height, receiver to bottom: 4.1 in.
    • Thickness, max: 1.2 in.

Made in U.S.A.

MAGPUL MOE K2 PLUS GRIP Armalite AR-10 A4 UPGRADE

MAGPUL MOE K2+ GRIP FEATURES

  • Replacement for AR15/M4 pistol-grip*
  • One-piece reinforced polymer construction with wrap-around rubber overmolding
  • More vertical grip angle than standard A2 grips
  • Unique backstrap design for proper trigger finger placement
  • Hard-polymer bottom edge to reduce equipment snags or grip damage
  • Includes a basic grip cap, but accepts optional Storage Cores for customized gear stowage

*NOTE: This grip will function properly with 7.62 NATO AR10/SR25 style of rifles but, depending on the make of the rifle, may or may not leave a gap between the backstrap’s ‘beaver tail’ and the receiver. This gap is purely aesthetic and will not affect function.

AR-10 A4 UPGRADE SCOPE-BROWE BCO COMBAT OPTIC FDE 65281BROWE BCO-002

BROWE BCO-002 COMBAT OPTIC SPECIFICATIONS

  • Magnification: 4x
  • Entrance Pupil: 32mm
  • Exit Pupil: 8mm
  • Eye Relief: 37mm
  • Length:  132mm nominal
  • Width: 67mm nominal
  • Weight:   17 oz.
  • Field of view: 7 °
  • Adjustment at 100 yards: .5 MOA
  • Adjustment: Internally adjustable prism
  • Reticle pattern: BCO Chevron with ballistic stadia lines from 300m to 900m
  • Ballistic Compensated:  7.62 x 51mm NATO
  • Color Day/Night: Red, Amber, Blue, or Green
  • Illumination source: LED
  • Illumination source controlled-Automatic: Flash programmable Microcontroller
  • Illumination source controlled-Manual: 10 days settings and 3 night vision
  • Battery Usage Life: 2000 hrs. Typ. (Min. 775hrs. on max brightness setting)
  • Housing Material:  Military Grade Pure Titanium – TiCP-2
  • Water Proof: 42m / 130ft.
  • Fog proof: Filled with dry nitrogen
  • Lens Coatings: Broad Band Anti-Reflective Coatings

 

BCO Utility Port

The BCO utility port is a sealed port on the backside of the battery housing.  This port can be used to update the operating firmware or customize the existing program.  It can also be used to plug in a remote pressure pad switch, so the SIC button controls can be placed at a secondary location on the weapon.  This port can also be used to import or export power.  This means that accessories such as lasers or mini red dots could be powered from the BCO battery.  Alternatively, the BCO utility port is capable of importing power, to run on an external power source such as a central power system.

 

Optical Design

The BCO optical design is based on an internally adjustable roof prism optical system with an etched glass reticle.  This design was incorporated to maintain a short overall length, a platform that has proven itself successful with currently deployed products.  All lenses are precision ground of the finest quality optical glass available and are broad band anti-reflective coated possessing excellent light gathering capabilities even under low light conditions.  The glass etched reticle incorporates an LED coupled with microprocessor technology and a cadmium-sufide photocell to measure target light levels, automatically adjusting the reticle to match target lighting conditions.

4x32 BROWE BCO-002 COMBAT OPTIC

4×32 BROWE BCO COMBAT OPTIC | BROWE BCO-002

ACOG vs BROWE! – While I have no experience with the Trijicon ACOG line of scopes their military acceptance and performance speak volumes. That said, for me the 4×32 BROWE COMBAT OPTIC BCO-002 is the easy choice for the AR-10 A4 Upgrade project. From a consumer perspective the BROWE BCO is the clear winner vs the equivalent ACOG. The BROWE is less expensive, runs on batteries and is constructed of titanium. Alternatively an ACOG is expensive, needs serviced every 10 years or so when the tritium dies and the housing is made of aluminum. Lastly Brian Browe is  good guy and we wish him much success. I selected the Larue Tactical QD mount. If I was to do it over again today the American Defense QD mount would be my first choice mount. I prefer the American Defense since being introduced to their mounts from my ATLAS BIPOD. Visit Browe to Purchase Direct.

The 4x32 BROWE® Combat Optic (BCO) is a state-of-the-art optic that delivers the best-in-practice features of high-quality optical glass, high precision machining, and rugged military design with unique, next-in-practice features that puts the BROWE® Combat Optic (BCO) at the forefront of its class. The BCO offers customers a modern designed, internally-adjustable, combat optic with many unique features, such as Single Intuitive Control (SIC), Target Light Sensor Technology, field-programmable BCO Micro-controller, and a vibration sensor – all packaged in a rugged and versatile titanium housing.

Single Intuitive Control (SIC)

The operation is simple and intuitive.  The idea is revolutionary.  The system rests in the OFF position or SLEEP mode.  The first press of the SIC button puts the system into AUTOMATIC mode. In this mode, the LED automatically adjusts to the ambient light conditions using the Target Light Sensor Technology.  The second press of the button puts the system in MANUAL mode.  It starts at the brightest day setting and cycles through ten (10) day and three (3) night vision settings with every press of the SIC button.  Holding the SIC button for more than three (3) seconds puts the system back to SLEEP mode, conserving battery life. Hitting the button again puts it back into AUTOMATIC mode. Simple. Intuitive. Effective.

Target Light Sensor Technology

Through extensive R&D, we’ve discovered that mounting a sensor in the light path behind the objective lens magnifies the incoming light and provides greater accuracy of the target light levels.  In AUTOMATIC mode, this key feature allows the BCO reticle to be properly illuminated even when the user and target are in dissimilar light and avoids sensor errors caused from ambient light.  More importantly, as an operator is on the move, the BCO will continuously adjust automatically. For example, light levels can vary extremely from streets to dark alleys and buildings. In today’s urban warfare, when a nanosecond can make a difference, there’s no time to search for a poorly illuminated reticle or make manual illumination adjustments.

BCO Microcontroller

The BCO Microcontroller is the brain of the operating system. Its custom program reliably and easily controls all of the electronic features. Unique to the industry, the BCO microcontroller is capable of being re-flashed with alternative programs via a sealed flash port on the back of the battery housing. This port can also be used to attach accessories such as a momentary remote tape switch.

Vibration Motion Sensor

The vibration motion sensor conserves precious battery life by putting the electronics in SLEEP mode if motion is not detected after two hours. Additionally, if the SIC button is accidentally depressed in a carrying case or storage rack, the system automatically turns off after three (3) seconds. The BCO has an average battery usage life of 2000hrs. with a minimum of 775hrs. on max brightness.  In SLEEP mode, the battery will maintain the full 10 year life expectancy of a Surefire Lithium 123A battery.

Housing Designed to Accept Accessories

Versatility is at the forefront of the BCO housing design.  So you’ll find multiple areas for mounting “add-on” accessories. For starters, the OD of the eye-housing is a machined 30mm diameter surface with a 2mm groove for locking on dust covers or an assortment of other accessories.  Plus, two mounting bosses are placed on top of the housing for attaching additional accessories. On the objective end, we added a 42mm x 3mm OD groove and threaded the ID for added versatility for accessories, such as anti-reflection devices, dust covers, and/or laser filters.

BATTLE ARMS DEVELOPMENT BAD CASS SA AMBIDEXTROUS SAFETY SELECTOR

Like Armalite the folks at BATTLE ARMS DEVELOPMENT were great friends with with this site. We were critical to their early success. Roger Wang got us hooked on BAD Ambidextrous Safeties. Fortunately at the time of this project They had just received a batch of BAD CASS selectors that were Cerakote FDE. It was meant to be.

Changing the AR-10 AP4 safety and upgrading it to the BAD CASS is pretty simple. I recommend doing this upgrade the same time as the pistol grip as the parts are interconnected.

Battle Arms Development – Combat Ambidextrous Safety Selector – Semi Auto (BAD-CASS-SA) for the AR15 Style Rifles and the ArmaLite, Inc.’s AR10®.  The Levers are detachable and interchangeable on both sides for maximum flexibility and user preference.  There are a total of (9) Lever Designs and (81) Possible Lever Combinations!  The BAD-CASS-SA is a must have for the “South Paw” and Ambidextrous Shooters!

What is different with the BAD-CASS family of safety selectors vs. the original BAD-ASS family of safety selectors are the way the levers are attached.  The DOVETAIL lever attachment of the BAD-CASS allows for superior strength and dependability by removing the stress from the screws.  Originally designed for military applications, the BAD-CASS Combat Ambidextrous Safety Selector is now available to all.

MIDWEST INDUSTRIES AR-10 GEN2 TWO PIECE HANDGUARD DROP-IN AR-10 A4 UPGRADE

MIDWEST INDUSTRIES AR-10 GEN2 TWO PIECE HANDGUARD, CARBINE LENGTH DROP-IN MI-AR10CHG2

Armalite AR-10 rifles do not have the same quantity and variety of upgrades available as the 308 AR AR 308 platform. There’s some fantastic free float handguards available but as the barrel was not getting replaced and despite aggressive marketing not every AR-15, AR-10, 308 AR, AR 308 needs a free floated barrel. Drop-in carbine length handguards are sufficient and the Midwest Industries part number MI-AR10CHG2 is one of the best options.

Drop-In handguards are very simple upgrade. Good hand strength and this special tool make the task even easier.

Midwest Industries two piece drop-in AR-10 railed forearm gives your ArmaLite AR-10 carbine all the accessory mounting versatility of Midwest Industries two-piece forearms. Four MIL-STD 1913 Picatinny rails contain 20 mounting slots each, and are laser etched with white alphanumeric position markings. Lower section may be left off to provide clearance for a grenade launcher, tear gas launcher, or shotgun. Direct replacement for plastic factory handguard—no gunsmithing or permanent alterations required.

Midwest Industries Two Piece drop In AR-10 Handguard MI-AR10CHG2 Description

♦ Made for use on ArmaLite AR-10 rifles
♦ TWO piece drop-in design, no gunsmith installation
♦ MIL-STD 1913 rails, T-marked for accessory location
♦ With four anti-rotation QD sockets for push button swivels
♦ Lightweight, rugged construction of hard coat anodized 6061 aluminum
♦ High quality, affordably priced, made in the U.S.A., with lifetime warranty

MAGPUL PICATINNY LADDER RAIL COVER

MAGPUL PICATINNY LADDER RAIL COVER PANELS offer very low-profile 1913 Picatinny rail coverage. The Santoprene material provide a rubbery surface for improved weapon control and rail protection. Easily cut for custom lengths, each panel fits one side of a carbine-length rail (18 slots). One panel per package. Manufactured by Falcon Industries, Inc.

 

MAGPUL PICATINNY LADDER RAIL COVER
GEISSELE Triggers For Sale AR 308 AR-10 AP4 UPGRADE

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308AR AR-10 Technical Link