Building a custom rifle allows the shooter to end up exactly with what he wants. Any barrel length, any cartridge, any contour, you name it… you are only limited by your imagination. Many custom rifles start out life as factory guns. Here is how we converted our Remington 700 AAC -SD (Advanced Armament Corporation) into a one of a kind, custom precision rifle.
The out of the box accuracy demonstrated by the Remington 700 Tactical 308 AAC-SD we tested was excellent. The entry level tactical rifle performed flawlessly and exhibited sub minute of angle (MOA) accuracy. The 20″ threaded barrel provided a quick handling package capable of delivering accurate shots under a variety of conditions. A full review can be found here.
Our proven Remington 700 Tactical 308 AAC-SD provided the action for our custom build. Without getting into a lengthy discussion about the pros and cons of specific actions, possibly the biggest advantage to the Remington 700 is the wide range of aftermarket parts available for it. In many ways, this is the AR15 or 10/22 of the bolt action rifle world.
In this article, our rifle will be transformed into a custom 243 Winchester precision rig that combines light recoil, with excellent external ballistics and commonly available brass.
We ordered the following items from Brownells for this article:
- Bartlein 1:8 heavy varmint barrel (749-008-389)
- Manson receiver accurizing kit (513-000-050)
- Manson receiver ring facing cutter (513-000-053)
- Manson bolt face truing tool (513-000-008)
- La Bounty bolt fixture (521-100-000)
- 3/8″ High-speed steel turning kit (080-000-835)
- High-speed steel 35 degree profile kit (080-000-836)
- 1/2″ threader (080-000-839)
- Starrett Dial indicator (749-007-761)
- Accuracy International AX chassis system (100-013-365)
- Hollands recoil lug (403-150-100)
- Manson 243 Winchester finish reamer (513-050-150)
- Viper’s Venom cutting oil (100-013-368)
- Brownells barrel vise (080-860-307)
- Brownells Remington 700 action wrench (080-800-700)
- Spuhr scope mount (100-011-207)
- Badger rail (093-306-060)
- Nightforce 3.5-15×50 F1 scope (100-012-582)
- OPS R3E2C muzzle brake (504-000-014)
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All lathe work was conducted on a Grizzly 4003G lathe.
A few notes on the donor action used in this article:
- an over sized bolt knob was installed, see “Tactical bolt knob installation“
- the bolt had been helically fluted by Kampfeld Custom
With the action removed, we can begin! The first step was to true, or blueprint the action. This process involved squaring the surfaces of the action and can be accomplished in a number of different ways. We used a Manson kit, which has provided us excellent results in the past.
The surfaces of our action were trued to the bolt hole in the center of the receiver. We performed the following operations:
- cut the minor diameter of the receiver threads
- cut the front surfaces of the receiver lugs
- cut the receiver threads
- cut the receiver ring (front surfaces of the receiver)
- cut the front and rear faces of the bolt lugs
- cut the bolt nose
- lapped the rear faces of the bolt lugs
- cut the bolt face
Performing these steps provided us a trued receiver ready to accept our barrel.
We like using Holland recoil lugs. The over-sized .250″ thick double lug has tapered draft angles to allow its easy release in bedding applications and is ground to ensure both faces are parallel. A pin was used to secure the lug in place.
The addition of an external bolt stop provides a nice custom touch. In addition to being easier to access then the factory trigger guard mounted stop, the external bolt stop is far less likely to bind up in field conditions.
While the action is in pieces, it was a good time to polish the raceways to ensure smooth operation of the bolt.
There are a number of ways to thread and chamber a rifle barrel and we have tried most of them. We have found them all to work satisfactorily. For this project we dialed in both ends of the barrel through the headstock. Our tail stock was painstakingly adjusted for second operations and our reamer was held in a Gre-Tan fixed (not floating) reamer holder.
A copy of the chambering worksheet that we used can be found here.
We used Viper’s Venom cutting oil as a lubricant with Brownells high-speed steel insert tools. This combination of cutting tool and lubricant provides an excellent finish on stainless steel barrels.
The chamber was cut in very light passes. To do this, the reamer was coated in Viper’s Venom and inserted into the chamber. The lathe was run at 70 RPM (our lathe’s slowest setting) and the reamer was slowly fed. The lathe was then stopped and the reamer retracted and cleaned. The process was repeated until the reamer reached full depth.
The reamer stop makes cutting a chamber to the correct head space easy. The initial adjustment was made by eye. A “go” gauge was held up next to the reamer and stop, and the stop was adjusted to cut too shallow. After the initial cut, the reaming depth of cut determined by feeler gauges was halved, and that value adjusted into the reamer stop. This process is repeated until the chamber is cut to depth. There is no sense in rushing here. If the chamber is cut too deep, the shoulder must be reset.
Since we planned on shooting long, high ballistic coefficient bullets, we made up a dummy cartridge. Our cartridge is 2.880″ long. The inside of the AICS-AX magazines used by the AX chassis system are 2.900″ long. Subtracting .020″ to allow the cartridge to feed gave us the 2.880″ length.
Since out reamer is cut to SAMMI specifications, the throat was not long enough to accommodate the round. The throat needed to be lengthened. To determine how much the throat needed to be extended, the existing throat can either be measured with a Hornandy overall length gauge, or as shown here, by measuring the protrusion from the rear of the barrel.
With the chamber work complete, it was time to focus on the muzzle. Our rifle was to be equipped with an OPS R3E2C muzzle brake as well as a thread protector for the applications where we wouldn’t want to use the brake.
This brake, like many other directional brakes on the market, needed to be timed. This means there is a top and bottom. On preexisting builds this is typically accomplished with the use of shim washers. On new construction, the preferred method is to time the brake on the barrel.
To time the brake, the brake was installed after the tenon was threaded and cut. The orientation of the top of the brake and top of the barrel were noted. The tenon’s shoulder was then incrementally reset until they aligned.
To determine how much the shoulder needed to be set back, 1 was divided by the number of threads per inch. In our case, 1/24=.042″. This means for every .042″ the shoulder is set back, the brake will turn one revolution. To make a half turn, divide this value in half, for a quarter turn by four and so on. So if the brake needed to be turned one half revolution, (.042″)(.5)=.021″. A .021″ cut allowed the brake to rotate one half a turn.
In practice, we made lighter cuts then needed to avoid taking off too much material. If the shoulder is set back too far, the shoulder needs to be set back for nearly one full revolution.
Final assembly in the AX chassis is conducted once the rifle was coated in Cerakote. To see how we applied Cerakote, check out our article here. The AX chassis, is an updated version of the very popular AICS chassis system from Accuracy International.
Check out these specs from Brownells:
The AX AICS (Accuracy International Chassis System) brings the ergonomic and functional benefits of the advanced Accuracy International AX sniper rifle system to the Remington 700 platform. A far superior chassis system suitable for any environment and mission, the AX AICS provides a degree of modularity and configurability that cannot be achieved with a traditional stock. Quick and easy to install, requiring no specialized gunsmithing, the AX AICS is available for short and long Remington 700 actions in .308 Win, .300 Win Mag and .338 Lapua Magnum families of cartridges. Built from polymer and alloy, the AX chassis is more than just a stock!
- Full length aluminum chassis. The stiffness chassis gives the rifle a rugged, environmentally stable platform to enhance accuracy and zero retention. The action is attached to the chassis by two bolts (supplied) and retained in a self-aligning vee block bedding system which eliminates the need for bedding.
- Folding chassis. When folded, the overall length is reduced by 8”. Ideal for rapid deployment from a vehicle, the stock locks in the folded position to avoid noise. Release by simply pulling the butt, the wear compensated hinge ensures total rigidity in the extended position.
- Pistol grip.
- Adjustable cheekpiece. The standard adjustable cheekpiece adjusts left/right as well as for height to obtain optimum cheek position when using night vision equipment or telescopic sights with large objective lenses.
- Butt pad. Chassis systems are fitted with a bolt-on soft rubber pad with 10 & 20mm spacers as standard.
- Bipod adapter. The chassis has a fixing point for Harris Bipods fitted as standard.
- Magazine. Surface toughened and finished with a multi-part, anti-corrosion, low friction coating. One 5 round magazine is supplied as standard. The chassis design makes loading faster and more positive – no need to lift the rifle.
- Forend mount assembly. 16” long action or 13” short action free float tube forend featuring a keyhole slot system for quick and securely attaching modular rail sections for mounting accessories. One 80mm rail and one sling loop included as standard.
In the past we have had excellent luck with the AICS systems. They eliminate a large amount of guess work building rifles. Unlike fiberglass stocks which require a little bit of skill to properly install, the AICS goes on easy and is hard to screw up. Since we are using a Jewel trigger, we needed to open up the inside of the chassis to allow it to function properly.
With the rifle fully assembled, we headed to the range with three different loads using Sierra 107 grain MatchKing in Lapua brass over Reloader 22 powder and Tula large rifle primers.
For load development, we fired multiple three round groups from 100 yards. The rifle was shot off a bench from a bipod with a rear bag. Results are found below:
|Load #||Velocity (FPS)/sd||Average Accuracy||Best Group @100yds|
|1||2885 sd 5||.650”||.464”|
|2||2952 sd 15||.659”||.543”|
|3||2996 sd 21||.511”||.301”|
Heading to a larger facility, we found the combination of light recoil, flat trajectory and accuracy allowed us to easily make hits in excess of 600 yards (the longest range available). We did fire one, five shot group at 300 yards which measured 1.882″.
We are pleased with the finished package. Our light recoiling rifle is capable of sub 1/2 MOA accuracy without extensive load development on the first run. We will report back when we get some more load development completed.
To customize your Remington 700, or for any other gunsmithing supplies, make sure you visit Brownells.
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