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Posted: 4/19/2008 5:46:51 PM EDT
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I have a 16" Rock River Arms flat top upper mated to an LCW lower, which will soon be used as my patrol rifle at work. A friend gave me an unknown brand two piece railed fore end and a nice aluminum fore grip which I had mounted up. To my dismay, the rail was not very solid which was exaggerated by the fore grip. Knowing that this would not do, I made a few calls and placed some orders for new stuff. Not wanting to have to worry about doing a dremel job on an action block a la LaRue install, I ordered this nice piece from Brownell's which I found to be made by DPMS: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eb7798600000017108AZN2TFq0cuM I found this to be a nice piece made from delrin, and mates with two pins to the upper as if it were installed on a lower: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eb5798400000017108AZN2TFq0cuM Using hollywood magic, here I am removing the handguards with ease (in reality it took my wife and I and a plastic hammer to perform, good riddance delta ring!): http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eb1798000000017108AZN2TFq0cuM |
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Next I removed the front sight base, supporting the barrel while I tapped out the pins: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eb0f8b100000017108AZN2TFq0cuM Then I removed the FSB, gas tube, and handguard ring: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eb3798200000017108AZN2TFq0cuM Using my DPMS armorers wrench I then removed the flash hider: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ebcf8bd00000017108AZN2TFq0cuM |
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Now it's time to remove the barrel nut, this took a little elbow grease and skinned knuckles: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eb9798800000017108AZN2TFq0cuM The whole nut/delta ring assembly comes off as one unit leaving just the barrel in the upper. The barrel nut/delta ring does not get re used, do with it what you will. http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ea2f8a300000017108AZN2TFq0cuM Now we are ready for the new parts. Here is what comes with the Daniel Defense 7.0 Lite rail, plus their armorers wrench which is hiding (sold separately): http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eb2f8b300000017108AZN2TFq0cuM |
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First to do is slide the locking ring over the barrel, the machined recess faces outward toward the muzzle: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ea4f8a500000017108AZN2TFq0cuM http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ea3799200000017108AZN2TFq0cuM Next is the barrel nut, I applied a thin film of anti seize compound to prevent galling between the steel nut and aluminum receiver: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ea5799400000017108AZN2TFq0cuM |
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Now install the barrel nut, it will only fit correctly one way, and you can see how it fits within the recess of the locking ring: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ea0f8a100000017108AZN2TFq0cuM http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ea1799000000017108AZN2TFq0cuM hand tighten the barrel nut, then install the DD barrel nut wrench and then torque to 50-75 ft/lbs torque, per instructions(always verify written torque measurements supplied): http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eaf799e00000017108AZN2TFq0cuM It is important to note that the locking ring will still have some play, as it is not held to the receiver by the barrel nut. It will be pretty much lined up with the gas port, verify that the port is not obstructed before installing the rail. Now slide the rail over the barrel and line it up with the locking ring: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eacf8ad00000017108AZN2TFq0cuM |
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As you can see there are 3 bolt holes on either side of the receiver. First insert two of the allen cap screws in the bottom most holes, muzzle to breach in direction: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548eaaf8ab00000017108AZN2TFq0cuM http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ead799c00000017108AZN2TFq0cuM Next, install the remaining four screws breach to muzzle, all should be hand tight only and somewhat loose at this point: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548ea8f8a900000017108AZN2TFq0cuM Continue to snug all six bolts in an alternating fashion until hand tight, line up the rail as necessary, mine needed the most minimal of adjustment. Once done, it lines up perfect and is rock solid, as the ring and rail clamp together around the barrel nut: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548e94f89500000017108AZN2TFq0cuM |
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Now reinstall the gas tube and front sight base: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548e9579a400000017108AZN2TFq0cuM Flash hider: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548e9179a000000017108AZN2TFq0cuM And any fore grips and accessories that you wish to mount: http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548e9f79ae00000017108AZN2TFq0cuM Re mount the upper to the lower, function check and go! http://shim1.shutterfly.com/procgserv/47b8da38b3127cce98548e9d79ac00000017108AZN2TFq0cuM |
| After mounting, I found the Daniel Defense 7.0 Lite rail to be rock solid and have ZERO play. I cannot imagine this rail being knocked out of alignment/loose during any real world circumstance that wouldn't otherwise render the rest of the rifle inoperable as well. I also noticed that the fore grip that I have installed had to be hammered on/off the old rail, whereas it slid snugly, but freely onto the DD rail. I also put a straight edge/level to the rail/upper and it was right on the money vertically and laterallyhope |
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Great post! When I installed my 10" Lite Rail, the biggest issue I had was aligning rail itself with the upper receiver. I used a low profile gas block under the rail. So I slid the assembled gas block over the barrel and mounted it without the rail installed as a guide. Then I removed it and installed the rail. I had to make a tiny correction before I was 100% happy with the alignment. To make small alignment adjustments, use a lead pencil to mark the mounting ring and the upper receiver. Then back the barrel nut off and re-index to the desired position. Careful not to bind the gas tube. It can cause the Bolt Carrier to impact the gas tube if you're causing deflection against the tube itself. |
| Bushman, the sentence states that since I did not want to have to dremel an action block, I went with the DPMS style instead of the clamshell type, perhaps I was not clear enough? I still had to do a tiny dremel job to the lower section, but it was no big deal and probably could be done with a utility knife. |
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| This my seem like a dumb newb question but I need it answered if possible because I have a Larue 12" I will be trying to install in a few days. After you snug the barrel nut up tight how are you torquing it? I KNOW a torque wrench is used, but a torque wrench doesn't fit onto a barrel nut. Do I need to buy some special armorer's torque wrench? Or can a standard torque wrench be applied to a standard armorers wrench?(i.e. DPMS wrench?) |
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