caporider

I personally would buy a new AR10 bolt and barrel extension and send both to someone like BHW or Criterion to build you a proper 6.5 Creedmoor barrel that works correctly with your AR10. Noveske used to make AR10-specific 6.5 Creedmoor barrels (they were accurate but heavy - I had a 20" one), but I believe they've stopped production on them.

The flash hider is a Vltor VC-301; it's threaded 5/8x24.

Yep, my Defender 10 also has a lower marked SPR Mod2A, and "multi" for the caliber.

Great pricing on some good ammo! Thanks for the tip.

The IMI mags are very nice and the followers ride smoothly in the bodies. Spring tension seems just right. I can load a full 20 rounds and seat the mag with the bolt closed. The windows are not "calibrated" like the ones on the Magpul LR25s, so not quite as useful but I guess they're good to see if there are SOME rounds remaining. I'll take more photos when I get a chance... As a quick update, I've shot the following ammo through the rifle so far: - PMC 147gr FMJ .308Win: 100% function over 90 rounds, very nice ammo; - Hirtenberger 147gr 7.62NATO: 100% function over 20 rounds, great value for the price; - FN 144gr 7.62NATO, vintage 1981: 100% function over 5 rounds, have a bunch of this so good news; - DAG 150gr Bimetal 7.62NATO: consistent short stroking, no-go in this rifle. No real accuracy testing, but my various targets seem to indicate a 1-2MOA rifle depending on ammo. When I get a longer range session I'll shoot some of my standard precision ammo, which is the Hornady 168gr Amax factory load.

Thanks all, the DEF10 is a blast to shoot and balances better than the other AR308s I've owned. Here it is with an IMI 20 round mag.

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 CAR10 heavy buffer with the UBR. I am thinking about cutting my standard Armalite AR10 carbine spring to 24 coils to mimic how heavybuffers.com mods their springs... 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 a red-illuminated .308 horseshoe reticle; I believe this config with the FDE anodizing and SDO-type lens caps was exclusive to RSR. Secondary is an Aimpoint Micro H-1 on a Burkett offset mount. Weight is 10.5lbs with no mag inserted. IMHO that's not half bad. Plus, the UBR pulls the weight toward the rear of the rifle, which in turn aids in balance. 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

Here is my new AR-10A (A10A4CBF). I just can't seem to stay away from .308 ARs. This is replacing a 16" DSA STG-58 carbine –– I just can't seem to get comfortable shooting FALs. As pictured, weighs a shade under 10lbs empty and about 11.5lbs loaded with 20 rounds. It's a bit under 9lbs with just the irons. Particulars include a Magpul STR stock, LaRue 9.0 handguard, KAC handstop, Troy M4-style gas block flip front sight, Vltor VC302 flash hider. The little box behind the M4S is a twist mount for the Aimpoint 3x magnifier. I also staked the receiver extension castle nut. After a brief 56-round zeroing session shooting FN 7.62 surplus (vintage 1982): (1) The Troy gas block mounted sight works fine as a backup front sight if you "lollipop" the target. Since this is how I shoot all my irons anyway, I'm happy. It was no problem to ding a 4" plate at 75 yards off a bipod. (2) Althought I did not shoot for ultimate accuracy today, the rifle seems to be about 2MOA using the FN surplus stuff and the M4S RDS. On a subsequent range session I will see what the rifle can do with Hornady 168gr Amax factory ammo and a Nightforce 2.5-10x32. (3) No problems to report, although with only 56 rounds fired that is probably not all that great a data point. The rifle uses a "H3" marked buffer; I may try a Slash-type heavy buffer. If the rifle is a 1MOA shooter I'll keep the LaRue freefloat handguard on there. Otherwise, I'm seriously contemplating a Magpul MOE midlength handguard to simplify things. Overall, I am quite happy with my AR10A.

Vltor VC-301 comp, VC-302 FH Battlecomp Enterprises (BCE) BABC Primary Weapons Systems (PWS) FSC30, PRC, Triad, CQB Comp

You don't need the Superformance ammo to get to 600 with a 16" barrel. The regular 168gr Amax load will do just fine. I've shot the 178gr Superformance load out of a number of 16" gas guns and results have ranged from just some extra recoil to smoked and popped primers. In fact, I ended up trading Hornady 400 rounds of the 178gr Superformance for the same number of 168gr Amax standard loads. As I understand it, Superformance ammo gets its MV boost from extending the area under the pressure curve, meaning pressures stay high for a longer period of time than with normal ammo. This can have an adverse effect on some gas guns, especially ones with shorter gas systems.

I think building .308 ARs is fun, but there is a level of frustration that isn't present with building AR15s, mostly due to the proprietary nature of .308AR parts and the lack of standardization among manufacturers. I have built or bought about a dozen .308ARs over the years and have bounced from precision rigs to carbines and everywhere in between. I now have a 20" 6.5 Creedmoor on a Mega MA-TEN upper/lower combo and a modified Bushmaster .308 ORC. One is for tack driving out to 1100 yards and one is for burning up surplus ammo pinging steel out to 500. I'll let you guess which is which... Neither is a go-to gun for social work or even hunting. I'm just so much faster with my AR15s on drills, manipulations, etc, and I have a great 6.8 rig for hunting medium-sized game and feral pigs. Plus, my AR15s are so much lighter. That having been said, nothing puts a smile on my face like slapping those steel plates with the authority a .308-based round brings to the game.

No failures, but recoil was extremely harsh and I could just tell the BCG was moving way too fast. Ejection was to my 4 o'clock in more of a spray pattern vs having all the casings fall in one place.

I just put a Clint Butler heavy CAR10 buffer (5.6oz, vs Bushmaster's factory 3.8oz buffer) and Superior Shooting System's flat wire AR15 length action spring into my ORC. Recoil is considerably reduced and everything operates much more smoothly. Brass is kicked to 2 o'clock in tiny piles - as expected given the upper's forward assist/brass deflector. No failures of any kind to report over a wide variety of surplus ammo and Hornady 168gr Amax factory .308. Just another data point for you to consider.

Hornady 168gr Amax factory loads have been very accurate in all my .308 ARs. The Amax does much better passing through transonic than the 168gr SMKs.

The SSA is a great trigger. I have two, one in my 5.56 SPR and one in my customized ORC .308. Works superbly in both. Enjoy!

The anti-rotation tab LaRue uses is easy enough to relieve using a file or a Dremel tool for various sized uppers. That barrel nut, on the other hand...

Nicely done, sir! I believe you would sell quite a few barrel nuts if you were inclined to make more... ;)

I think I see a LaRue AR10 handguard on there. Does that mean the KR7 uppers accept AR10-threaded barrel nuts, or did you have a custom barrel nut made? Thanks.

Have you tried an o-ring and extra power extractor spring? My ORC is overgassed, so yours may be even more so. This will cause extraction problems because the BCG is cycling before the brass casing has had time to contract off the chamber walls after firing. I'm going to try a Slash-type heavy buffer and a Tubbs flat wire action spring to see what happens. You could also try an Armalite extended collapsible stock receiver extension vs the standard commercial spec AR15 extension on the ORC. I haven't spec'd the chamber on my ORC, but if it is not 7.62 NATO you could always take a finish reamer and correct the chamber. The chrome you remove won't be worth writing home about, and it will improve reliability with surplus ammo.

I really like my Bushmaster ORC .308, which is basically a DPMS gun with some Bushmaster specific features (both companies owned by The Freedom Group/Cerberus Capital). I've upgraded it with a few select parts, but my total outlay is still under $1500. Of course, it'll shoot fine as configured from the factory. In particular, I like the 4150CMV chrome lined barrel and bore, which is a step up from the 4140 non chrome lined barrels typically used by DPMS at this price point. Note that the upper receiver is the new lower DPMS-standard height, which is .060" lower than previous uppers. This will affect which freefloating railed handguards you can use if you want the top rails to line up perfectly. Upgraded parts for my rifle include: - milspec receiver extension (I've standardized on milspec across the board on my ARs) - Magpul MOE handguard - Magpul MIAD pistol grip - Magpul CTR stock - Armalite 0.750" clamp-type FSB - BCM Gunfighter Mod 4 charging handle - Geissele SSA two stage trigger The rifle is a good shooter - no malfunctions to date with West German DAG ('92), FN 144gr, and Magtech 150gr. I don't normally shoot for groups, but I'd estimate the gun is capable of 1.5-2MOA shooting surplus, closer to 1-1.5MOA shooting match rounds.

Got a .308 ORC on Monday, shot it with about 60 rounds of various surplus 7.62 as well as some Magtech .308. No malfunctions using LR20 mags, felt a bit overgassed. Swapped the commercial receiver extension for milspec, knocked out the pins and removed the shaved FSB, added an Armalite clamp-on FSB (for now) and a bunch of Magpul furniture. Also swapped out the 5/8x24 threaded A1 flash hider for an A2. Curiously, the gas tube rides ABOVE the barrel nut teeth, so Bushmaster just torqued the barrel nut to spec and left it slightly off kilter. However, since the MOE handguard indexes to the barrel nut teeth, I had to crank the nut a tad tighter to get everything lined up. No big deal, just something to note. I will eventually have Adco drill and pin a new F-marked FSB. Why not just wait for the Bushmaster MOE .308? Well, I wanted the FSB to be correct and perfectly aligned (which Adco will do for sure) and I did not want the MOE stock, greatly preferring the CTR instead. These .308 ORCs do feature the lowered top rail DPMS uppers, so an F-marked FSB should line up correctly. Weighs 7.8lb empty, 11.8lb as pictured with a full LR20 mag. That, to me, is entirely reasonable for a .308 AR. [img width=810 height=539]http://personal.visualitymedia.com/personal/ar308/moe308_rt2.jpg [img width=810 height=436]http://personal.visualitymedia.com/personal/ar308/moe308_lt.jpg

Hey all, Just found this site, but I've built, owned, and shot a multitude of custom and factory 308ARs over the years: LR308, DPMS SASS, AR10A4C, AR10T, LaRue OBR, LMT 308MWS, KAC SR25 EMC and EMR, LWRCI REPR, and Mega MA-TEN. However, what I don't know still far outweighs what I do know, so I'm glad to find this online resource for us guys stricken with the 308AR disease. I currently own and shoot a custom MA-TEN in 6.5 Creedmoor with a Noveske barrel. It's accurate and fun to shoot but it is definitely too heavy to be anything but a precision rig. My next 308AR will be something like the Bushmaster 308 MOE, with better pointability, less weight, and less complexity. Thanks everyone, and be talking to you.

Actually, the Bushmaster .308 lower features a standard AR-type removable trigger guard. This is one of the details that differentiate it from its DPMS brethren.