Chambering, Threading, Break-In – Ultimate Reloader

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Last fall Hornady announced the 22 ARC (Advanced Rifle Cartridge), a round optimized for performance from an AR-15, but also powerful in a bolt action.

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About 22 ARC

Hornady’s 22 ARC is a very new cartridge and not all information is publicly available yet.

It accepts a 22 caliber/0.224” bullet and has a case length of 1.525”. COL is 2.260”— AR-15 mag length,—and its case head measures 0.441” (same as 7.62x39mm, 6.5 Grendel). It has a 30 degree shoulder angle and takes a small rifle primer. A 1:7 twist barrel is optimal, yielding approximate 2,800 fps velocity with an 88 grain bullet.

Bill of Materials

Even though the 22 ARC is designed for use in the AR-15, it didn’t stop me from building a bolt action. I waited some time for a 1:7 Ballistic Advantage heavy contour barrel blank to pair with a BAT TR Action in a Foundation Centurion stock. I added Hawkins Precision DBM M5 and a custom AICS magazine with a Primal Rights Conversion Kit

A V2 EC Tuner brake and Cerakote finished it off. 

It’s worth noting I selected the BAT TR for its wide range of features. It has a Remington 700 footprint, integral recoil lug, integral 20 MOA rail, tactical bolt knob, fluted modular bolt (recessed nose), and 1 1/16” x 18 threading. (This modularity is why I build all my Ultimate Reloader Custom Rifles on the BAT TR.) I also had it handy from my 6mm ARC build.

The Centurion is one of Foundation’s most popular rifle stocks. This micarta stock dampens vibrations but doesn’t flex or warp with weather/temperature changes. I wanted something incredibly stable and easy to shoot off a bench for this project.

I chambered the barrel on my new Precision Matthews PM-1440HVT-2 lathe with a cast iron base. This is an incredibly hefty machine and investment, but one I believe is worth it for the increased rigidity. I used Manson reamers/gauges as well as my custom rigid reamer holder. Manson’s 22 ARC rougher and finisher reamers were part of Hornady’s rifle builders kit to help get the industry ready for the 22 ARC, but I used 6.5 Grendel gauges. (22 ARC has the same base to datum and shoulder angle as 6.5 Grendel.)

Machining

This was my first time using a Ballistic Advantage barrel for a bolt action build. I’d previously had great success with them in AR’s and I was very happy with how it machined.

Pre-Dialing the Barrel
Bulk Drilling Chamber

I started with pre-dialing and drilling the bulk of the chamber before checking it with an indicator (final dial).

Final Dial

Next I bored the pre-drill true and turned and threaded the tenon.

Boring the Pre-Drill True

I ran the reamer 0.200” at a time, making subsequent smaller plunges, referencing the BAT action print.

Reaming the Barrel

I didn’t use pressure flush while cutting the chamber this time as I don’t have it set up with the new lathe. Finishing and polishing followed after I verified proper headspace. 

Turning the Tenon at the Muzzle

With the breech end completed, I flipped the barrel, dialed it in, and parted and faced off the end. I then zeroed the Z-axis, turned down the tenon, cut thread reliefs, cut threads, then cut the recess/crown. I decided to thread the muzzle ⅝ x 24 to accommodate the large number of muzzle devices I have with this threading.

Threading the Tenon

Cerakote and Laser Engraving

Cerakote customization is one of my favorite things about rifle builds. I chose Coyote Tan Cerakote for the barrel and while I was a bit hesitant at first, I’m happy with how it contrasts with the black stock and action.

Cerakoting barrels isn’t rocket science, but it does take tremendous attention to detail. I degreased and masked the barrel to prevent coating the threads, blasted the barrel, then unmasked and cleaned it. After cleaning I masked it again, mixed the H-235 Coyote Tan and applied the coating three times, flash curing it each time. I then let it cure for two hours at 250 degrees Fahrenheit in my Light Armor oven before deep engraving the barrel details with a 50W fiber laser. 

Installing the Barrel

I installed the barrel using the Short Action Customs bravo barrel vise and modular action wrench. To me, installing barrels is fun. I keep my barrel vise on SAC’s vise stand for easy access, then insert the proper bushings (1.200”) with drywall tape and secure the barrel in place.

I needed the #4 head for the BAT TR in the action wrench and torqued the action to 70 ft-lbs. I also did a final headspace check at this time. 

Barrel Break-In

We kept things simple in the snow, shooting three shot groups at 100 yards with Hornady 88 grain ELD-M and 75 grain ELD-M factory ammunition.

The 88 grain ammunition averaged 2822.3 fps with a 0.240” group. I need better chronograph data for the 75 grain ammunition, but the three shots measured 0.373”. (I did make some adjustments to the EC tuner to get these groups.)

Hornady 88 grain 22 ARC Break-In Results

Conclusion

Even though the 22 ARC is said to be an ideal AR cartridge, it’s great in a bolt gun. It has very reasonable recoil and great versatility. I look forward to doing load development, particularly with Hornady’s new 22 caliber 62 grain ELD-VT bullets and their 22 caliber 80 grain ELD-X hunting bullets.

Get the Gear

Ballistic Advantage Barrel

BAT TR Action – Used in all our Ultimate Reloader Custom Rifles!

Foundation Centurion Stock

Hawkins Precision DBM M5

Primal Rights 6BR AICS Conversion Kit

EC Tuner Brake V2

Precision Matthews PM-1440HVT-2

Manson Reamers/Gauges

Short Action Customs Bravo Barrel Vise

Short Action Customs Modular Action Wrench

SAC Vise Stand

Hornady 22 ARC 75 grain ELD-M Ammunition 

Hornady 22 ARC 88 grain ELD-M Ammunition

Hornady 22 caliber 62 grain ELD-VT Bullets 

Hornady 22 caliber 80 grain ELD-X Bullets

Coyote Tan Cerakote H-235

If you’re interested in taking the Cerakote Certified Applicator training, I would suggest enrolling ASAP as there’s a bit of a waitlist. If you’ve taken the class, consider the advanced course!

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Thanks,
Gavin Gear

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