Building a Custom Precision Rifle: Deviant 6.5×47 Lapua

July 4, 2014Bill MarrGunsmithing0

Precision rifle competitions seem to be rapidly expanding in popularity. Whether the shooter is stretching his rifles legs on F-Class competition or competing in a Tactical Rifle match, an accurate rifle helps a shooter achieve his goals.

Show up with your 308 and while you will be able to compete, you’ll be shooting against a bunch of guys with lighter recoiling and flatter shooting cartridges. I decided to chamber this rifle in 6.5×47 Lapua. This relatively flat shooting and mild recoiling cartridge feeds well from AICS and AW style magazines with no modifications.

I used the following parts from Brownells:

Deviant short action (100-012-650)
Bartlein HV 1:8.5 6.5mm barrel blank (749-008-388)
Badger M5 bottom metal (093-000-055)
Jewell HVR trigger (100-002-559)
Cerakote sniper gray (100-003-747)
Nightforce F1 3-15×50 MLR2.0 scope (100-012-583)
Spuhr Ideal scope mount (100-011-207)
Atlas bipod (100-012-045)
Atlas bipod adapter (100-012-057)
6.5×47 Lapua brass (749-007-672)
Lapua Scenar-L 6.5mm 120 grain OTM bullets (749-015-484)

Here are some features about the Deviant custom action from Defiance Machine

Pre-hardened materials, prevent tolerance changes when heat treated
Standard footprint allows for installation on a variety of aftermarket Remington 700 stocks
Defiance Primary Extraction design significantly increases initial extraction and ensures smooth bolt cycling
Wire EDM-cut, full-length lug ways provide smooth bolt operation and surpassed strength and rigidity
One piece bolt allows for unmatched strength
Custom spiral bolt fluting provides a unique appearance
Action is machined from 416 stainless steel
Bolt is manufactured from 4340 steel
Integral 20 MOA mil spec Picatinny mount
Includes integral 0.250 thick, precision ground, recoil lug
Bolt handle threaded for interchangeable knobs
Extractors are M16 style, allowing for improved strength
Short Action magazine well is cut for use with Remington BDL style magazines or detachable box magazines

My favorite thing about the Deviant action is it takes the Accuracy International double column magazines. These protrude about as much as the AICS 5 round mags, but hold 10!

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All lathe work was conducted on a Grizzly 4003G lathe.

I decided to begin by rough cutting the barrel to length 22". — I decided to begin by rough cutting the barrel to a length of 22″.

I am fluting the barrel on the milling machine. I'll be using a rotary table with chuck and a tailstock to index the barrel. I place the barrel in the set up and use a dial indicator to make the taper parallel to the x-axis of the mill. — I am fluting the barrel on the milling machine. I’ll be using a rotary table with chuck and a tail stock to index the barrel. I place the barrel in the set up and use a dial indicator to make the taper parallel to the x-axis of the mill.

I keep making small adjustments in the rotary table positioning until the indicator remains within .001" over the length of the taper. — I keep making small adjustments in the rotary table positioning until the indicator remains within .001″ over the length of the taper.

A PTG 10-tooth 3/16" (3/32" radius) fluting cutter is secured in a collet. — A PTG 10-tooth 3/16″ (3/32″ radius) fluting cutter is secured in a collet.

On my mill, I've found running the cutter .090" deep around 550 RPM and 4-4.25 inches per minute provides excellent results. — On my mill, I’ve found running the cutter .090″ deep around 550 RPM and 4-4.25 inches per minute provides excellent results.

You will notice a slight burr on the edge of the flutes. These are easily removed during the finishing process with abrasive cloth. — You will notice a slight burr on the edges of the flutes. These are easily removed during the finishing process with abrasive cloth.

I hold the barrel in the headstock of my G4003G lathe between two spiders. A range rod with bushing is placed in the bore and I dial the bore in with a .001" indicator. I then repeat the process with a .0001" indicator. — I hold the barrel in the headstock of my G4003G lathe between two spiders. A range rod with bushing is placed in the bore and I dial the bore in with a .001″ indicator. I then repeat the process with a .0001″ indicator.

Here is a view of the spider. Note the 4 brass tipped screws that allow me to gimbal the barrel. — A view of the spider. Note the 4 brass tipped screws that allow me to gimbal the barrel.

I begin by cutting the tenon to the appropriate length and diameter.

A relief cut needs to be made at the tenon shoulder. My threading tool can't cut right up to the edge. — A relief cut needs to be made at the tenon shoulder. My threading tool can’t cut right up to the edge.

I make a light pass with the threading tool and verify the lathe is cutting 16 threads per inch.

The threaded tenon. The barrel now needs to be timed to ensure a "rib" is top dead center on the barrel. This is done by taking minor cuts against the tenon shoulder until the rib is at the top. — The threaded tenon. The barrel now needs to be timed to ensure a “rib” is top dead center on the barrel. This is done by taking minor cuts against the tenon shoulder until the rib is at the top.

I use a .705" piloted counter bore to cut the bolt nose recess. — I use a .705″ piloted counter bore to cut the bolt nose recess.

I secure the reamer in a GTR Tooling fixed reamer holder. A reamer stop is attached to the reamer.

When the reamer stop hits the barrel, I can measure how much deeper the chamber needs to be cut.

With the go gauge in the chamber, the bolt and action are screwed on. A feeler gauge is used to measure the remaining gap. This is the depth the chamber still needs to be cut.

When the bolt closes on the go gauge, and not the no go, the chamber is cut to the proper depth. — When the bolt closes on the go gauge, and not on the no-go, the chamber is cut to the proper depth.

Before I remove the barrel from the lathe, I radius the outside edge of the bolt nose recess and break the edge of the chamber. The radius on the bolt nose recess aids in feeding. The radius on the chamber edge, prevents the cartridge case from scratching against a sharp edge.

To crown the barrel I dial in the bore on the lathe. I'm using a Gre-tan tooling #2 range rod with a .0001" indicator. Range rods have a provision for a bushing and a gradual taper. The rod is center by the bushing and the taper. — To crown the barrel I dial in the bore on the lathe. I’m using a Gre’-Tan tooling #2 range rod with a .0001″ indicator. Range rods have a provision for a bushing and a gradual taper. The rod is center by the bushing and the taper.

I use a high-speed steel boring bar to cut a crown .090" deep with a 45 degree pull back. I start by making a flat bottom recess with the boring bar and the retract my lathe compound at 45 degrees to make the pull back. — I use a high-speed steel boring bar to cut a crown .090″ deep with a 45 degree pull back. I start by making a flat bottom recess with the boring bar and then retract my lathe compound at 45 degrees to make the pull back.

To remove any burrs, I use a #2 piloted 45-degree center drill. The tool is held in my reamer holder and removes any burrs near the crown.

Here is the finished crown. I polished the outside edge to leave a small radius with 220 grit abrasive cloth. I really like the way these crowns look.

The McMillian A5 stock I am using comes with an inlet for a Remington Varmint contour barrel. I use a thin sharpie to mark the new barrel channel. — The McMillan A5 stock I am using comes with an inlet for a Remington Varmint contour barrel. I use a thin sharpie to mark the new barrel channel.

I've had good luck shaping barrel channels with hand tools like this barrel channel tool. — I’ve had good luck shaping barrel channels with hand tools like this barrel channel tool.

I use the mill to inlet the stock for the SIRS forward night vision mount.

The stock needs to be cut so the bolt stop can function.

A quick cut on the milling machine provides professional looking results. Notice the small chip in the gel coat, this will be sanded out later.

Before I remove the stock from the mill, I dry fit everything to make sure it all fits. — Before I remove the stock from the mill, I dry fit everything to make sure it all fits correctly.

In order to align the SIRS rail, I wrap tape around the barrel to center it in the SIRS. When the top is clamped on. the SIRS will not move, allowing it to stay aligned during the bedding process.

The metal is coated in spray release agent and clay is used to pack any voids. I place a little bit of Marine-tex behind the lug on the action to make sure I don't have an air bubble later. — The metal is coated in spray release agent and clay is used to pack any voids. I place a little bit of Marine-Tex behind the lug on the action to make sure I don’t have an air bubble later.

Mating surfaces of the stock are coated in a layer of Marine-tex. Notice I used painters tape to make clean up easier. — Mating surfaces of the stock are coated in a layer of Marine-Tex. Notice that I used painter’s tape to make clean up easier.

I spread a light layer of Marine-tex on the mating surfaces of the SIRS night vision mount as well. — I spread a light layer of Marine-Tex on the mating surfaces of the SIRS night vision mount as well.

I secured the muzzle end of the barreled action in the vise and place the stock on the action and gently tighten both action screws. I keep a lot of cotton swabs on hand to clean up the squeeze out. — I secured the muzzle end of the barreled action in the vise and place the stock on the action and gently tighten both action screws. I keep a lot of cotton swabs on hand to clean up what gets squeezed out.

I take my time to ensure the epoxy is cleaned from all visible areas. — I take my time to ensure that the epoxy is cleaned from all visible areas.

I leave the rifle in the vise and allow it to dry for a 24 hours. — I leave the rifle in the vise and allow it to dry for 24 hours.

Once the epoxy has set, I clean up the excess on the milling machine. All metal is coated in Cerakote except for the bolt, which is coated in KG Gunkote. The tolerances are so tight, I was worried that the Cerakote would possibly bind the action. The stock was coated in Duracoat camouflage and I headed to the range.