Project: Civilian Marksmanship Competition Rifle Build(continued) Day5

Project: Civilian Marksmanship Competition Rifle Build(continued) Day5

Barrel Installation

To get the best accuracy you need to true the face of the receiver and get rid of any play between the barrel and the upper receiver. Any bit of play will show up on the target downrange.

To true the receiver face you will need some tools and pending on how tight your lapping tool and how much coating is on your receiver you may need to use a drill. 

Lapping tool I bought from Brownell's 

Below is the lapping compound I used its just 

You will spin it back and forth to true the face of the receiver to make everything even.

The next step is trying to get rid of any play and gaps between the barrel and upper receiver. Any play will show up downrange when shooting. The goal is to eliminate any play to reduce barrel whip.

This process will take some trial and error. We are looking for the tightest fit possible.

Currently, I am using this stainless shim stock. Use a scissor to cut to size.

 

After you have found the perfect fitment next step is to install the barrel nut. 

This barrel nut and free float tube is specially designed to free-float forend, but keep the appearance of a stock M16 or AR15 foregrip.

https://www.whiteoakarmament.com/service-rifle-forend-kit.html

Use a little grease or anti-seize compound on the receiver threads and install the new barrel nut. Tighten to 35 foot pounds, then continue tightening until the next notch lines up with the gas tube hole in the upper. If you feel that you can not reach the next notch without using excessive torque, sometimes backing off and retightening the nut several times will allow you to get a little more rotation on it. You can use the new gas tube as an alignment tool. With the end of the gas tube through the hole in the delta ring, and the upper receiver, you should be able to place the other end of the gas tube directly over the gas port hole in the barrel without putting any stress on the gas tube. Once you have the barrel nut tightened to your satisfaction install the lock ring and screw it all the way onto the barrel nut.

After you're torqued, you'll want to align the spring and c-clip so that the gas tube can fit through. Take care not to scratch your finish. Apply tape if you must.

Screw the float tube onto the barrel nut. You want to screw the tube far enough onto the nut that when the front sight is installed you have clearance between the end of the tube and the front sight base. Keep in mind that if you have a GI contour barrel, the front sight will be about .035 away from the shoulder when you install the pins due to the fact that we no longer have the handguard cap sandwiched between the shoulder and front sight. Keep this in mind when you slide the front sight on to check your clearance. If you have a WOP or WOA barrel, they were contoured with a float tube in mind and you will want to slide the front sight all the way against the shoulder. 

Tighten float tube. Once you have determined where the float tube needs to be, unscrew the lock ring until it touches the float tube, but do not tighten. Now, leave the lock ring where it is and unscrew the float tube. Put a small amount of removable Loctite on the end of the barrel nut threads. Now, screw the float tube back on the nut. As you screw it on the Loctite will be distributed on the threads. The reason we did it this way was that we do not want any Loctite on the lock ring. You will understand why when it is time to rebarrel. After you have the tube screwed back on to your predetermined position, back it off about 20 degrees and hand tighten the lock ring against the tube. Now, using a strap wrench tighten the tube against the lock ring until it is level. You can determine the correct position by sighting along the top of the rifle and through the notch in the end cap for the gas tube. This notch should be in line with the gas port hole in the barrel. You can also check it by making sure the sling swivel lug is level. 

NOTE: If you think there is even the slightest possibility of scratching what you're working on wrap it with tape.

A trick to get everything lined up easier is to put it upside down then torque the gas block. 

The gas block I am using is from White Oak Armament. 

Can be found here: 

https://www.whiteoakarmament.com/picatinny-750-clamp-on-gas-block-for-service-rifle.html

Torque Spec: 30 inch lbs

Installing the crunch washer and flash hider you want to align the vents upward evenly. These are designed to break up flash but also prevent dirt and dust from kicking up, so it vents upward.

Project: Project: Civilian Marksmanship Competition Rifle Build Day 4(Continued)

 Project: Project: Civilian Marksmanship Competition Rifle Build Day 4(Continued)

Upper receiver build. After getting my Criterion barrel back from Cerakoting I decided that this would be a good time to polish the feed ramp and smooth things out for better performance.

User a Dremel and some polishing compound with the cone-shaped buffing attachment this process is fairly simple. The goal is to get rid of the machining and smoothing things to polish. Do not try to change angles we are just trying to remove rough spots.

Note: It's a good idea to plug the chamber with a cleaning patch or paper towel. to limit chances of compound going down the barrel. Also, after completely clean the barrel and chamber thoroughly.

I used the  white and green compound start with the green then finished with the white compound. I bought these giant bars from a truck stop.

Polishing the ramps is very simple, you just need to take your time.

Project: Project: Civilian Marksmanship Competition Rifle Build Day 3(Continued) Inlay work

 Project: Project: Civilian Marksmanship Competition Rifle Build Day 3(Continued) 

Inlay work. After Engraving. I add black paint to make things more detailed and visible. I will be using black as I did on my previous 300 Blackout Project. 

Now when you start with this be sure to have water standing by Rubbing alcohol. I would recommend 90% alcohol over 70% it's better to use when swiping and cleaning the excess off. Use cue tips as well for edges and harder spots. 

at this point just let it set up and dry. Pending on the paint you can also choose to bake it.

NOTE: If you are heating it be sure to use an oven you don't plan on using for food.