View Full Version : Armalite DEF10 build

26 June 2015, 10:45
So here is my Defender 10 with the Armalite 15" KeyMod rail and UBR. Function has been 100% so far over about 70 rounds of PMC 147gr FMJ. Both the IMI 20 round mags and the PMAG LR 25 round mags work great, hold the bolt back after the last round, and drop free full or empty. I'm using a standard AR15 carbine spring and a heavybuffers.com AR10 heavy buffer with the UBR.

I also used a little jig I got from Rainier Arms a while back to dimple the barrel for the set-screw type low-profile gas block. I tried to use one of the clamp-on gas blocks I have laying around but none would adequately clear the inside of the handguard.

Primary optic is a TA11D with .308 horseshoe reticle; I believe this config with the FDE anodizing and SDO-type lens caps was exclusive to RSR. Secondary is an offset Aimpoint Micro H-1 on a Burkett offset mount.

Weight is 10.5lbs with no mag inserted. IMHO that's not half bad.


The Armalite 15" freefloat KeyMod rail deserves special mention. First, it does not just clamp onto the barrel nut. In the photo below, the red lines indicate where the very beefy bolts that clamp the handguard together also interface with grooves on the very large barrel nut to ensure the handguard does not slide forward. Once mounted, the Armalite handguard isn't going anywhere.

In addition, there is a pocket on the right side of the handguard that captures the ejection port door rod so you don't need to use a longer AR10(T) type rod with this freefloat handguard.

Finally, notice the sleeves on the bolts? Those ensure you can't overtighten the bolts and break them.

The Armalite unit is very well thought out, IMHO. It is also very reasonably priced.


Very happy with this rifle! However, the little red guy with horns that sits on my left shoulder keeps whispering about swapping the barrel out for one in 6.5 Creedmoor so I can shoot handloads using the new Berger 130gr AR Hybrid bullets... :P

26 June 2015, 16:10
Lot of win in that pic. How much does she weigh unloaded?

Edit never mind I see it now. I'm blind, sorry.

26 June 2015, 16:14
Sir u are the Pimp

1 July 2015, 08:48
Updated the DEF10 config a bit with an AR308 MIAD pistol grip and moved the Aimpoint Micro forward. The IMI mags work great!