by Scott Johnson

arbuildnohgs

 

In the last installment of our Easy AR Build, we barreled our upper receiver and installed the gas block. One of the advantages to our simplified build plan is using the Midwest Industries G3 M-Series handguard kit, which includes the barrel nut and installation tool. Unlike the original USGI system, this barrel nut does not have to be torqued out of the way to allow the gas tube room to fit into the receiver. Also, the handguards themselves provide a 1913 rail running along the top, five QD sling swivel attachment sockets and M-LOK slots around seven sides. The MI G3s are surprisingly lightweight and narrow enough to grip easily. Although there are five lengths available, we went with the 15″ since they almost fully shroud the barrel, protect the gas system and allow for the maximum amount of easy upgrades or modifications in the future.

 

 

arbuildhgalign

 

Since we’ve already installed the proprietary barrel nut, installing the rest of the MI G3 kit is as simple as loosening the the two socket head cap screws on the bottom of the handguard and sliding it all the way back, over the barrel nut. There is a small tube of adhesive provided for coating the outside of the barrel nut, if the user wants both a physical and chemical bond to lock everything together. The bottom of the handguards also have an anti-torque plate with “wings” that should end up on each side of the upper receiver. This is also held in place by the same two cap screws. Some folks with extra chunky, custom billet uppers have reported problems with the anti-torque wings, but everything fit like a charm on our Aero Precision upper. When tightening the two screws down to 55 inch pounds, do keep an eye on the alignment of the handguards to make sure everything ends up square.

 

arbuildflashcan2

 

After the handguards are installed, the Kak Industry Flash Can goes on the the end of the barrel. Since it is basically a symmetrical tube with a funnel shaped interior, this muzzle device does not require timing or crush washers. Installation is simply a matter of carefully lining up the threads and screwing the can onto the barrel. There are 3/4 inch wrench flats on the back for snugging it up. The Flash Can is not a flash suppressor or one of those monster muzzle brakes that will wash backblast over everyone around you. Rather, it just serves to “point” the noise and expanding gasses down range.

 

arbuildch

 

Moving to the other end of the AR’s upper half, we’re ready to install the bolt carrier and charging handle. The charging handle goes in first, with a bit of a trick. We’re using the POF Archangel ambi charging handle for our preparedness oriented build. The original milspec design only has a latch on one side of the handle. Ambi latches, allow the handle to work with a pull on either side, simplifying the use of the weapon in difficult situations. The Archangel manages this task with a bit of flair with large “wings”, either of which can release the latch. When installing the charging handle for the first time, take note of the two tabs that stick out of the side of the handle body, just over an inch from the end. They prevent the handle from escaping the charging handle slot at the top of the upper receiver. The trick is to first insert the handle into the larger, round hole in the rear of the upper reciever. Push the charging handle slowly forward, with slight upwards pressure. About two and a half inches in, the tabs should slide up through a cutout inside the upper receiver, allowing the handle into the charging handle slot.

 

 

arbuildbolt

 

Once the handle is in place, the bolt carrier can slide in under it. The bolt carrier assembly is one of the most important parts of the rifle, as far as reliability is concerned. Our build is using the Sharps Balanced Bolt Carrier Group. It is complete and ready to drop into the rifle, right out of the box. Sharps basically re-engineered the fifty year old parts with upgraded materials and functionality. However, they stayed close enough to the original plans, that generic spare parts will still work on a rifle that has been upgraded with the Sharps assembly. There are two main parts to this complete bolt carrier group. First is the Relia-Bolt, which is crafted from S7 tool steel. It has specially rounded and tapered locking lugs that avoid jamming on carbon buildup and bits of debris that would cause problems with the traditional square lugged design. This is paired up with the Balanced Bolt Carrier, also made from S7 steel, which should deliver a smoother ride than the original. All of these parts are coated with NP3 PLUS, a slick layer of nickel/Teflon, which protects the metal and makes cleaning easier.

 

arbuildchbolt

 

Installing the bolt carrier group is just a matter of lining up the gas key with the notch under the charging handle and then sliding the carrier into place. It is easier to do this with the ejection port cover open, so it doesn’t try to stop the bolt. Also, before installing, it is a good idea to put some oil or CLP on a clean cloth and wipe everything down to get a thin layer on the surface of the parts. The NP3 PLUS coating is surprisingly slick already, so there is no need to soak everything.

 

arbuildback

 

After the bolt slides home, the upper is complete. The rear of the bolt carrier should be flush with the rear of the upper receiver. The charging handle should stick out slightly above the other parts.

 

arbuildclose

 

The upper and lower receivers are held together by the two captive pins. Mating the two halves together is just a matter of pushing both pins out of the lower, as far as they will go, and then sliding the upper into place. Pushing both pins back in will secure the two halves together. It is common practice to leave the front pin in place and just use the rear pin to open the gun for most cleaning and maintenance. Since our AR build is now complete, next time we’ll have to throw on some optics and go shooting!

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