Official Armalite AR-10 Lower Receivers | AR-10A | AR-10B

Armalite AR-10 Lower Receivers!

Armalite AR-10 Series “A” Lower Receivers can utilize Magpul LR 308 PMAG Magazines as well as other DPMS LR-308 compatible magazines!

Armalite AR-10 Series “B” Lower Receivers utilize Armalite proprietary magazines originally derived from M14 magazines!

As if the 308 AR versus AR-10® platform debate isn’t confusing enough Armalite brings confusion to their own platform. Armalite AR-10 lowers are available in two styles. The original AR-10 A series and the AR-10 B series.

Why does Armalite offer two different AR-10 lowers? Original Armalite “waffle”  magazines are actually the basis of DPMS LR-308 and KAC SR-25 magazines. During the 1994 Bill Clinton Assault Weapon Armalite decided to switch designs to the modified M14 magazines to ensure customers would have an ample supply of 308 magazines.

Armalite AR-10 Lowers

Armalite AR-10 lowers will not win any beauty contests but when you buy authentic AR 10 lowers you are buying battle tested hardware that has withstood the test of time. That’s more than most other 308 AR manufacturers can say. The Armalite AR-10 is the real deal.

Picture of

Official Armalite AR-10 Lower Receivers

AR-10 is the registered trademark owned by Armalite to prove it. No other firearm is an AR-10 no other manufacturers weapon should be referred to as  an AR-10. Armalite is the only AR-10® period. Referring to any other brand 308 AR as an AR-10 only adds to the confusion of the platforms

BUILD AN AR 10 | Armalite AR-10 Rifle

Do you want to build an Armalite AR-10 Rifle?

Armalite the Only AR-10 - BUILD AN AR 10 or do you really want to build a 308 AR?

Armalite the Only AR-10


So you decided you want to build an AR-10 and your internet search delivered you to this site and that’s a great start. The problem is years of misinformation from word of mouth, published media and now the internet has steered many shooters down the wrong path in both purchasing rifles and building their own from parts bought online. To clear this up and educate visitors we will start with a brief little historical information and some misconceptions.

ARMALITE is the ONLY AR-10 Rifle

The AR-10 is a trademarked model designation of a rifle model from ARMALITE. No other large frame AR in .308 should be referred to as an AR-10. This is the reason I started referring to other branded weapons as 308 AR Rifles (AR308).

Inevitably I get email and negative comments on the subject but here’s why I stick to my guns in using proper naming. That reason is compatibility. These large AR rifles do not share the same interchangeability as their AR-15 counterparts and that is very important. I like to use analogies when this subject comes up. All muscle cars are not Mustangs, all bolt action rifles are not model 700’s and all Cola’s are not Coke. ARMALITE is the ONLY AR-10. If you want to build an AR-10 head over to Armalite and order an authentic AR-10 UPPER RECEIVER/AR-10 LOWER RECEIVER. I promise you it is the only lower receiver stamped AR-10.

There is no MIL-SPEC AR-10 or 308AR Rifle

There is no Mil-Spec AR-10 or 308AR. Any marketing material stating otherwise is misleading. What can be made Mil-Spec is materials and finishes. Dimensionally there is no MIL-SPEC with regards to parts. The interchangeability and that’s where the confusion of the platform comes in to play. The 308AR platform is full of inconsistency and a lack of interoperability.

Armalite itself has two different styles of AR-10, DPMS has multiple receiver heights on their LR-308 rifles, the DPMS SASS has a proprietary barrel and gas system. Then there’s the DPMS G2 which is an entirely new platform all together. Rock River Arms, POF , all more different than the rest. Once again if you want to build an AR-10 visit Armalite.

If you want to build a 308AR and have some flexibility look towards companies like Aero Precision and Mega Arms as solid bases to begin a 308AR build. Their hardware is first rate and very generic in the way you want it. Of course there is other equally suitable brands but you need to do your homework in advance.

The AR-15 was derived from the Armalite AR-10

There is a misconception that the AR-10 is based on the AR-15. This is completely false. First off AR in AR-10 and AR-15 stands for “ARMALITE RIFLE” and not assault rifle. The AR-10 was developed by Eugene Stoner in 1956. The AR-10 was re-scaled one year later and became the AR-15.


DO YOU STILL WANT TO BUILD AN AR-10 or would you prefer to build a 308AR? If you still want to build an AR-10 I suggest buying a complete rifle directly from the Armalite. Building an Armalite AR-10 from parts will be a costly endeavor with no benefit over purchasing a rifle from Armalite. If you now realize and understand you want to build a 308AR by all means browse the pages of this website and have at it. The experience is quite rewarding.

I suggest visiting the following links before you proceed.












308AR AR-10 Primary Build kit


Picture of a 308 AR Bolt Catch Screw Bolt Catch Pin


Early on at we did a page that referenced the the point that the Armalite AR-10 utilized a BOLT CATCH ROLL PIN same as the Armalite M-15 (AR15) rifle while the DPMS LR-308 308 AR and similar rifles utilize a BOLT CATCH SCREW. Well despite that page we still get many questions about this small part. Based on these messages I decided a simple picture might be easier to understand in this day of sort attention spans. While I believe there are a small minority of 308 AR manufacturers using BOLT CATCH ROLL PINS just as there is an AR-15 manufacturer or two have adopted the BOLT CATCH SCREW feature. This post is meant to make folks aware of the differences.



  • AERO PRECISION BOLT CATCH SCREW – Aero Precision refers to this part as the M5 Threaded Roll PinOur threaded roll pin is used in multiple applications, including for the bolt catch on our M5 Lower Receivers and for the forward assist on our Upper Receivers. Made from stainless steel, it has a 6-32 thread pitch and is designed to be installed with a 1/16″ Hex Key Wrench.Note: This product is already included with our M4E1/M5E1 Enhanced Uppers, M4E1 Threaded Uppers, M5 Upper Receiver and our M5 Lower Receiver. It is not necessary to be purchased separately. This individual product is available for customers who have lost or damaged their existing threaded roll pin.

    Works With:

    • M4E1 Enhanced Upper Receivers
    • M4E1 Threaded Upper Receivers
    • M5 Upper Receivers
    • M5E1 Upper Receivers
    • DOES NOT work with our M4E1 Lower Receiver
    • DOES NOT work with a standard AR15 Lower Receiver

At this point I cannot definitively state what 308 AR rifle manufacturers use the threaded BOLT CATCH SCREW or the BOLT CATCH ROLL PIN. Feel free to contact us and let us know whether your lower utilizes a BOLT CATCH SCREW or BOLT CATCH ROLL PIN

308 AR AR-10 Manufacturers who utilize a BOLT CATCH ROLL PIN










Can I shoot 308 in an AR 15

Can I shoot 308 in an AR 15? Picture comparing a MATEN 308 AR lower receiver with an AR 15 lower receiver

Can I shoot 308 in an AR 15? Picture of a 308AR/AR-10 and AR15 receiver set

Can I shoot 308  in an AR 15? That is still by far the number one question I receive personally from shooters looking for more power and range than the AR15 and any of it’s available calibers are able to deliver. Of course the simple answer is “NO” but humans are curious by nature and we take nothing at face value. We like to know “Why” or in this case “Why cant I shoot 308 in my AR-15?”. I could simply explain that the cartridge is too long for the magazine and action.A .308 proportioned barrel is too large in profile to adapt to an AR-15 receiver etc… BORING…. I thought it far better to take a bunch of pictures and throw them up an a single page. Please by all means share the pictures and the page just give credit and share the link where possible. Enjoy

Visit the 308 AR 15 page pictorial at this link

As a side note to this post if there is something you would like to see covered at this site please drop us a line and let us know. Lets sort out this AR15 308 AR AR-10 stuff in a way regular folks can understand. View our contact page here

Note: This page is referring to .308 Winchester caliber. AR-15 rifles can shoot .308 bullets in a caliber known as .300 Blackout. .300 Blackout utilizes a .223 casing necked for a 30 caliber (.308) bullet

Can I shoot 308  in an AR 15?

AR15 Trigger in a AR-10 Rifle | AR Trigger Question

AR15 Trigger in an AR-10

Can you use an AR15 Trigger In a AR-10 or 308 AR?

AR15 Trigger In a AR-10 or 308 AR: One of the most common questions we get on the forum or facebook is “CAN I USE AN AR 15 TRIGGER IN A AR-10 or 308 AR?“. Well the answer is not black and white. Most AR15 triggers will in fact physically fit and function in a current AR-10 and 308AR rifle. However the reason  AR-10 and 308 AR specific triggers exist is for one main reason, military primers. The primers in military ammo often require more energy to ignite the primer than .223/5.56 ammunition. The way they extra energy is achieved with a heavier hammer and a more powerful hammer spring. If you look closely at the picture above you can see that Pact in their AR Gold and SR Gold Triggers increases the height of the hammer slightly to gain the extra mass.

AR15 Trigger In a AR-10: There are many shooters successfully using AR-15 TRIGGERS in their AR-10 and 308 AR rifles however the risk is reliability. Our suggestion is always utilize a trigger that is specifically stated by the manufacturer to work in a AR-10 and 308AR rifle. There is typically no cost difference unless you want to utilize the least expensive triggers or a AR-15 TRIGGER with a TRIGGER JOB. In either of those cases I would have to ask why bother? Remember a quality trigger is the single best improvement you can make to any AR 10 and 308AR rifle. Skimp elsewhere.

AR15 Trigger In a AR-10

308 AR and AR-10 Trigger Suggestions:

AR15 Trigger In an AR-10 and 308 AR









308 AR Bolt Catch Screw | AR-10 Bolt Catch Pin Comparison

Picture of a Falkor Defense 308 AR Bolt Catch Screw Bolt Catch Pin

308 AR Bolt Catch Screw or Threaded Roll Pin

308 AR AR-10 Bolt Catch Pin – The bolt catch pin, one of the smallest parts on the AR 308, AR-10 and AR-15 platform weapons is a part that can stop an AR-10 308AR build dead in it’s tracks if you didn’t purchase the correct one or the correct LOWER PARTS KIT for your STRIPPED LOWER RECEIVER. Here’s why. The AR-15 platform  uses a roll pin and that’s taken for granted when shooters move up to the AR-10 and 308 AR platforms. Unfortunately this is where the topic gets muddy.

Picture of Armalite AR-10B Lower Parts Kit 10LRPK-T

Armalite AR-10B Lower Parts Kit 10LRPK-T

Armalite AR-10 rifles use a traditional roll pin setup in the AR-10 lower receiver so their Lower Parts Kits obviously include the pin. If you use an AR-10 LPK on your non Armalite 308 AR you will need to order the threaded “Bolt Catch Screw” seen elsewhere on this page. I typically keep the Armalite LPK’s on hand as well as a few of the bolt catch screws.

Picture of an Armalite AR-10 and AR-15 EL0220 Bolt Catch Roll Pin

Armalite AR-10 and AR-15 EL0220 Bolt Catch Roll Pin

The Armalite AR-10 utilizes this roll pin, Armalite part number EL0220 which is the same as their M-15/AR15 rifles. Alternatively DPMS LR-308 based weapon utilize a proprietary hybrid pin/screw (mentioned above).

Picture of a DPMS AR 308 Bolt Catch Screw

DPMS AR 308 Bolt Catch Screw

The DPMS 308 Bolt Catch Screw is essentially set screw who’s threads have been removed from one end creating a hybrid screw type pin. Now unfortunately though not all DPMS LR-308 platform based LOWER RECEIVERS utilize the hybrid BOLT CATCH PIN. Some manufacturers utilize the roll pin method identical to the Armalite AR-10.

Picture of 308 AR, AR15 and  AR-10 Roll Pin Tools

308 AR, AR-15 and AR-10 Roll Pin Tools

The process of installing the Bolt Catch Pin is probably one of the most difficult tasks for the inexperienced to perform. Not done properly it’s easy to damage the finish of your lower or worse, break something. Fortunately a little grease, a roll of masking tape and some special roll pin punch make it easy.  Visit our AR-10, 308 AR Roll Pin Tools Page