Drew Eckhardt

At 38-42 lb-ft, the little extra shearing castle nut staking isn't noticeable.

13.5 pounds empty Aero Precision M5E1 15" mlok builder set, Krieger 20" M110 AMU profile barrel, Magpul CTR stock with LaRue RISR plus bag rider, Nightforce NX8 2.5-20x50 on a Nightforce 20 MOA 1.375" extended mount, Harris 6-9" bipod

I ordered an Armalite AR10 spring a few weeks ago with plans of trying Eugene Stoner's proven combination sometime, but will be pleasantly surprised if that happens in the next few months.

I'd try that in a heart beat except the parts are back ordered with an unknown delivery date. I can get an A5 buffer tube and H3 buffer from other sources, but the spring is a wild card. Anyone know the Armalite spring parameters? I have a Fulton Armory .308 rifle spring measuring 12 5/8" long with 39 .078" coils, but no clue how close it is.

The Geissele reaction rod design is suboptimal except for swapping muzzle devices. There's a lot of friction between barrel nut and receiver threads. Try to separate a tight enough one with torsional resistance only applied through the locking lugs and you'll break the barrel extension index pin or upper receiver. You want a design like Midwest Industries uses which locks barrel and upper together through a sail engaging the receiver charging handle channel. The Magpul armorer's wrench also isn't the best choice. For tight barrel nuts a breaker bar with socket will give you more leverage and work for non-USGI applications. I like the PRI USGI barrel nut socket. For castle nuts and rifle buffer tubes you're better off with a crowfoot having less distance to the square drive. I like Spike's castle nut socket which fits into tight spots, like the room left with a Smoke Composites carbon fiber stock. I prefer a USGI tool over a 5/8" crowfoot for rifle tubes because it's completely flat. SK breaker bar, Stahwille split beam torque wrench with fixed square drive installed for crowfoot use, .308 Midwest Industries reaction rod, PRI barrel nut socket, Spike's castle nut socket, USGI tool.

Aero Precision .308 large lever Breach charging handle from Brownells, 2.8" wide. I can't wait to have something easier to grab around my scope eyepiece and LaRue RISR.

I bumped my buffer weight to 5.3 oz, swapped in the Springco orange spring, and installed my Sentry 8 adjustable gas block. It moves less than before the adjustments, but still has bolt over base malfunctions using the DPMS magazine when set for minimum gas to lock open on empty. Given reliable function with the ASC and a PMAG, I'm going attribute my problem to the longer DPMS feed lips and not use those magazines. Bolt over base malfunction using DPMS magazine, but just enough gas for bolt hold open on empty: Which I attribute to feed lips slightly longer than my other magazines I'm just going to leave the DPMS magazines in a box and enjoy my rifle:

That is, it locked open when I let either magazine run dry. It ran all the way through the 10 round ASC magazine, but had repeated hiccups starting with a fully loaded 10 round DPMS magazine. Starting with the bolt latched it fed reliably from both magazines.

I finally got around to scoping and shooting my Aero Precision M5E1 15" mlok builder set with an Aero Precision BCG , 20" Krieger M110 AMU profile barrel, and Precision Armament M4-71 brake. Running both Federal M80 and Hornady 168gr match It locked open on every shot and ran reliably with my ASC magazine; but firing M80 had repeated failures to feed with a DPMS brand magazine having longer feed lips where the bullet ends up at the top of the extension and it might be a bolt over base situation although no ammunition damage results. What would the ideal buffer weight be from 3.4 to 5.3 ounces (I have a heavier buffer body that adds 0.3 ounces and pair of tungsten weights that each add 0.8) to run reliably and spot hits through my scope switching to an adjustable gas block,and Sprinco orange (11 1/8", 28 coils, .074") spring? Specifics at the time included 1. An LR308 recoil system using an AR stoner buffer 2. weighing 3.7 ounces 3. 2.5" long 4. In a 7 inch deep carbine tube 5. With an AR Stoner spring, 11 1/2" long, with 28 coils, using 0.074" wire 6. Using an AR -10 rifle gas system 7. With a 15.5" tube 8. 9. 10. 11. .875" gas journal diameter, gas port between my .092" and .093" +0, -0.0002" pin gauges 12. ASC magazine which works well on left, DPMS magazine which fails on right. The DPMS feed lips are Magpul Pmag length although I haven't tried one of those yet. The barrel extension has M4 feed ramps, receiver hardly any which would be OK on a .223 AR Other less relevant specifics are a Magpul CTR stock set to A1 length, LaRue RISR that gives me a solid cheek weld but moves to allow charging, Geissele Hi Speed DMR trigger, Nightforce NX8 2.5-20x50 Mil-XT on a Nightforce 1.375" 20 MOA extended Unimount, and Harris 6-9" bipod. It was laser accurate, recoiled less than my 9 pound .223 AR, and was perfect apart from the magazine sensitivity that has me speculating about having too much gas or too little buffer.

A 5.3 oz 308 carbine buffer, Springco orange spring, and SLR Rifleworks Sentry 8 adjustable gas block. With a 3.7 oz 2.5" buffer, AR Stoner spring measuring 11 1/2" with 28 .074" coils, .100" gas port, and proper AR-10 rifle length gas on my 20" barrel I'm under-buffered leading to bolt-over-base malfunctions running a DPMS magazine with longer feed lips than my ASC magazine which works reliably. The extra 5/8" of receiver behind the pistol grip made an A2 stock way too long, so I took my first shots using a CTR stock on a 7" milspec extension set to A1 length of pull two notches in. In the process, I learned about large frame AR gas and recoil system balance. Gas system is correct Krieger M4 barrel ramps with Aero Precision "rifle" receiver would be OK on a small AR

Howdy! I live in Silicon Valley, which is part of California where on July 1st our government required us to lay in a lifetime supply of modern sporting rifles before 12-31-2016. My July panic of 2016 build that I'm slightly behind on is a .308 DPMS (brand) LR-308 with a 20" M110 profile barrel. I was never happy with the accuracy from my previous .308 MSR - a STG-58 metric FAL built on an Entreprise receiver. I love an AR15 with a good 2-stage trigger, and figured I'd like a .308 AR as much. I've found that without actual milspec blueprints part fits vary a lot more than with the AR15, and was spending my time arriving at a stripped upper which is a good fit for my lower and barrel extension. I'm in good shape now beyond wanting bigger take-down/pivot pins, and will get signed off on the techshop metal lathe to make those myself if I can't find any to my liking.