Reloader’s Press

Many decades have passed since the introduction of the 223 Remington and its acceptance by the Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) in 1963. Since that time, many companies have attempted to capitalize on its success by building cartridges that meet the 2.260-inch overall length restriction for function in AR-15 rifles. The widespread military adoption of this cartridge as the 5.56 NATO undoubtedly added to its popularity. It also meant that surplus ammunition, brass and bullets were plentiful for those looking for a cheap option for plinking and practice. The 223 Rem/5.56 NATO has been the most popular .22-caliber centerfire cartridge for decades running.

While there is no doubt the 223 Rem/5.56 NATO is a very effective cartridge, it has seen widespread use in militaries around the world. It has a proven track record when it comes to varmint hunting and has even seen success on larger game. For years, it has been a favorite of mine for hunting coyotes, I can appreciate having an AR-15 on the stand with me should multiple coyotes come in or a rapid follow-up shot is needed. However, it always seemed like more performance could be squeezed out of the AR-15 despite all of the restrictions when it comes to cartridge design.

I have been an early adopter of many of these cartridges, such as the 22 Nosler, which used the same bolt face as the 223 Rem/5.56 NATO. Thanks to the rebated rim, a larger case and a faster twist, the 22 Nosler offered increased performance over the 223 Rem/5.56 NATO. In contrast, the 22 Nosler did have some speed bumps along the way. However, it does deliver on its promises of increased performance in terms of energy and velocity. However, for use in an AR-15, some experimentation with adjustable gas blocks or spring and buffer weights can be required for proper function and timing. However, this is not exactly uncommon when playing with new cartridges in the AR-15. The SAAMI Maximum Average Pressure (MAP) was set at 55,000 pounds per square inch (psi), which is the same as the 223 Remington. Since the 22 Nosler has more case capacity, the end result was comparatively higher velocity and pressure.

Another effort to challenge the popularity of the 223 Rem/5.56 NATO was the 224 Valkyrie, introduced by Federal in 2017. It promised even faster twist barrels to stabilize the latest, heaviest, .22-caliber bullets with high-ballistic coefficients (BC), yielding improved trajectories at extended ranges. This cartridge used the same case head as the 6.5 Grendel and required the appropriate bolt face and a barrel swap to convert an AR-15 chambered in 223 Remington or 5.56 NATO. The SAAMI MAP was set at 55,000 psi.

Despite the increased performance over the 223 Remington, neither one of these cartridges ever really caught on for a number of reasons that I don’t have time to get into. I still have two rifles chambered in 22 Nosler, an AR-15 and a Nosler M48 bolt-action rifle. They both still see a lot of field use and are typically in the rifle rack and rotated through when culling cattle-crippling rodents or they can be found in rotation for predator control.

Fast forward to 2023 and Hornady announced its new 22 ARC cartridge, a high-performance cartridge that utilized the same bolt face as the 6.5 Grendel and could launch high-BC bullets at impressive velocities. It could also function in an AR-15 while a standard AR in 5.56 NATO could be converted with a bolt and barrel swap. While some tuning with buffers may be required depending on the situation, it is a simple enough swap to make. The cartridge itself was based on the 6.5 Grendel necked down to .22 caliber and some other minor tweaks. The SAAMI MAP was set at 52,000 psi for this cartridge for use in AR-15 rifles. Interestingly enough, Hornady has released two different pressure levels, one for “gas guns” and the other for “bolt guns,” which runs the pressure up to 62,000 psi for increased performance. This is very similar to what they did with the 6mm ARC cartridge and it offers increased versatility and a level of performance only available to the handloader.

To the dedicated handloader, this is nothing new. The 224 Grendel, also known as the 22 Grendel, has been around for quite a while now. It just hasn’t become popular despite the impressive performance it delivered. It was a cartridge I had wanted to play with, but the lack of popularity kept me from jumping on board. Besides that, I had two 22 Nosler rifles that worked well and satisfied my needs. However, After Hornady announced this new cartridge, that all changed and I decided it was something that many folks would be interested in.

With the announcement still fresh, a few phone calls were made to various companies, with most of them saying the reamers for the cartridge were all 2-6 months out. I called my friend, Dave Kiff at Pacific Tool & Gauge, who previously had reamers for the 22 Grendel. In chatting with him, it was quickly found that the chamber dimensions were nearly identical and there was not much difference between the 22 ARC and the 22 Grendel he had been chambering. This was confirmed by examining the reamer print, which is good news because it means that previous load development for 22 Grendel could be used to cross-reference for the 22 ARC. A minor adjustment to seating depths may be required to duplicate results between the two cartridges but they are very similar. Kiff informed me he could have a rifle built and sent my way months ahead of others. We decided to build the rifle around his Drakkar action, which offers an extended magazine box, so no matter which bullet I selected, I would have plenty of room to play with seating depth. It also features an integrated rail in 0- or 20-MOA options in addition to the use of #8 screws for secure mounting of the rail to the action. Even under heavy recoil or a morning on horseback to a favorite coyote stand, it remains secure.

With the action selected, an order was promptly placed for a .22-caliber (1:7 twist), 20-inch, carbon-fiber-wrapped barrel blank from Proof Research. A carbon-fiber stock from AG Composites in the Carbon Desert Night pattern was selected with an Arca Rail, QD sockets and extra texturing added. Once all the components arrived, everything was sent to Kiff, who personally built the rifle for this article and even signed the receiver. When the rifle showed up, I was over the moon excited. I quickly mounted a Leupold VX-3 4.5-14x 50mm scope and set out to shoot a group using the new Hornady 62-grain V-Match ammunition. The rifle assembled an impressive 20-shot group measuring just 1.10 inches, discounting the first shot out of a brand-new barrel. This rifle could shoot!

After that, the rifle was a constant companion in the truck, on the tractor, or in the field. Wherever I went, the rifle went. In the meantime, while I was field testing the rifle, an order was placed with Leupold for the new Mark 4 4.5-18x 52mm optic. This would put this rifle in its final form for load development, hunting and match use. When it came to components, I selected Lapua 6.5 Grendel cases since I had 200 unfired cases on hand. I attempted to size the Grendel brass down in a single step using a Hornady Custom Grade resizing die. Sadly, this resulted in crushed cases, so prior to using the Hornady die, cases were run into a Mighty Armory 6mm ARC die backed off to just size the neck down. From there, they were run through the Hornady full-length sizing die to make 22 ARC brass from Lapua 6.5 Grendel cases.

Now that I had 22 ARC brass, the next step was to chamfer and deburr the cases. For this, I used an RCBS Brass Boss case prep center. The cases were then primed using a Frankford Arsenal Hand Primer. All charge weights were dispensed using a Redding BR-30 powder measure, then weighed on a Creedmoor Sports TRX-925 Precision reloading scale and trickled to proper weight using an RCBS powder trickler. All charge weights were accurate to .04 grains, which is likely a bit overkill, but it is a habit I have developed over the years. The final step was to seat a bullet. A Hornady Custom Grade seating die with their new click-adjustable micrometer seating stem installed was used to seat all bullets. At the end of the day, I had more than 190 rounds loaded and ready to put to the test.

As can be seen from the accompanying handload table, there were several impressive loads. All testing was conducted in a single day to limit environmental conditions as much as possible. The test procedure was to fire 20 rounds and then let the barrel completely cool. The barrel was cleaned every 80 rounds using Wipe Out from Sharp Shoot R. Across 49 different loads and 195 rounds, the average group size was .63 inch! I can only imagine what this rifle could do with a good, consistent load and having more time to cool the barrel between strings. Certainly, more testing is needed with more statistically significant sample sizes. However, the initial results are certainly impressive.

I have a hunch that now that the cases are fireformed, accuracy and consistency will only get better. Overall, the rifle was a joy to shoot as the recoil was extremely pleasant, especially with the Nosler SR-30K cutting down on the muzzle blast and report. In the next issue of Handloader No. 352 (October – November 2024), I will pick up where I left off with more details on the rifle, cartridge and more loads using fireformed brass. Sadly, I am out of space in this issue.

If you would like to watch the accompanying video to this article, check out the video titled “Creedmoor Sports Enhanced and Adaptive Press Heads” on our YouTube channel – Handloader TV.