I am going to go 40*.
223 Rem Ackley Improved–More Speed, More Power
Why the AI?
Some shooters own a half-dozen .223s and they just want to try something different. That natural curiousity can be reason enough to try a .223 Rem Ackley Improved. But there are also three very logical (and quantifiable) reasons to go with this chambering.
Reason Number One is Speed. Depending on the powder, brass, and barrel length, the Ackley version of the .223 Remington will, typically, deliver from 100 to 140 fps more speed with any given bullet. (Light bullets gain more.) That makes a difference, particularly for varminters looking for a flatter trajectory and more explosive effect on target.
Likewise, long-range shooters will benefit from improved ballistics. The AI’s greater case capacity will let you run a given bullet faster, or let you step up to a heavier bullet with better BC.
Reason Number Two is Brass Stability. The .223 Rem AI has a 40° shoulder. Once the cases are properly fire-formed, the steeper shoulder resists case growth. You’ll find the AI brass is extremely stable and you won’t have to trim the cases as often. Many .223 AI shooters also find they can reload the case many times before full-length sizing is required.
Reason Number Three is Availability of Components. Compared to other “hot rod” cases such as the 22 Dasher or 22 PPC, .223 brass is cheap and plentiful. You can buy new IMG (Guatemalan) brass from Wideners for $89 per 1000 cases. Top Brass (Scharch Mfg.) offers fully processed, once-fired Lake City military brass for the same $89/1000. And many shooters already have an ample supply of .223 Rem commercial brass. Rather than let that old .223 brass languish–Ackleyize it.
How Much Extra Powder Capacity Will I Get?
The .223 Remington is a compact case, with relatively limited case capacity. Ackleyizing the case adds roughly 7-8% to the capacity. The exact amount of the increase in case capacity depends on your brass and the reamer used to cut the chamber, but the range is between 2.2 grains and 2.8 grains. It’s reasonable to figure you’ll gain about 2.5 grains extra capacity.
What About Dies?
The .223 Rem AI is the most popular of the Ackleyized cartridges. Hence a wide selection of dies is available. Redding, RCBS and Lee all sell .223 Rem AI (40° shoulder) sizing and seating dies. Wilson also makes inline seater dies and neck-sizing dies for use with arbor presses. Our current favorite set-up would be a Redding Type “S” full-length bushing die combined with a Wilson seater. While it’s a good idea to have a full-length die (or body die), the stability of the .223 Rem AI case means that, if you avoid max loads, you can get by with just neck-sizing your brass for a few reloading cycles. This is one of the advantage of the Ackleyized case.
The inexpensive Lee dies work fine. Graymist reports: “Lee Pacesetter 223 AI dies were purchased through Midway for less than $26.00. The brass only has to fit in [my one 223 AI rifle], so unlike the 223 Remington brass I am only partially sizing the neck of the case. Runout has been under .002″ with the Lee dies. I recently had a friend run a 223 AI reamer in a Forster 223 Remington seating sleeve so I could use a Forster Ultra Seater die. The only real advantage with the Forster seating die is I can use the micrometer adjustment when seating different bullets.”
Where Can I Find 223 AI Load Data?
Apart from Graymist’s .223 AI page, and Reloaders’ Nest, there is limited online load info for the .223 Rem AI. Sierra plans to add a .223 AI section to its reloading manual, but that is still months away. Jason Baney has acquired a .223 Rem AI and we will be adding data to this page over time. But until all that info arrives, it’s best to start with .223 Rem loads and work up. Since the .223 Rem AI only has about 8% more capacity than the parent case, the best thing to do is to start with a known, good load for the .223 Remington and then work up your AI load incrementally. With the light bullets and a fast powder such as H335, you’ll probably use about 1.5 grains more powder in the Ackley case. But this is only a guideline. Since .223 Rem brass varies up to 2.6 grains in internal capacity from one headstamp to another, you’ll have to work out your own best AI loads incrementally.
What is the Best Method to Fire-Form the Cases?
Fire-forming .223 AI brass is very easy compared to some of the other Ackleyized wildcats. This is because the overall geometry doesn’t change very dramatically other than the shoulder angle. You’re not blowing the shoulder forward into the neck. Graymist simply loads a stout charge of H335 with 40gr V-Maxs: “Fireforming was straight forward. Put the 223 cartridge in the rifle and pull the trigger. None of the complications I had when forming other Ackley Improved cartridges. I lost no cases when fireforming. Fireforming loads are superbly accurate, so don’t waste them on punching paper. Form your brass while you hunt.” Jason Baney, to save on barrel wear (and bullet costs), is fireforming using pistol powder and cornmeal: “Try some Bullseye powder along with cornmeal and a patch to give you 95%+ formed cases. In my testing, I used 8 grains of Bullseye, topped with 12 grains of cornmeal (you have to settle it a little bit to fit it all in), with half a .22 caliber (1/2″ x1″) patch stuffed in the neck to secure the charge. This will give you a mostly AI-formed case with no bullet. The shoulders will not be as sharp as a case that has been 2-times-fired with a full-house load, but in my opinion, the cornmeal-forming procedure will help get to a true ‘Ackley’ load sooner. NOTE: Though there is no bullet, the cornmeal charge is still very dangerous–use the same precautions you would employ with normal ammunition. Likewise, use hearing protection.”
What Brass Should I Use?
You can get excellent results with many different brands–Lapua, Lake City, Hornady, Winchester, and IMG to name a few. But Graymist did an interesting comparison test in his .223 AI, comparing Lapua with Winchester: “After fire forming, I recorded four groups with the Lapua brass. The average group size was .293″. (Individual groups ran .221″, .366″, .389″ and .195″). The .293″ average Lapua group size is about .197″ smaller than the average of the six best groups fired previously in this rifle using Winchester brass.” How does the Lapua brass hold up over time? “After six firings the Lapua primer pockets remained tight, bolt closure was still easy, and no cases exceeded the 1.760″ maximum case length. (Most of the Lapua cases, when formed, measured 1.750″). At $40.00 per 100, Lapua .223 Rem brass is two times more expensive than Winchester or Remington but it represents a substantial improvement in load consistency in my .223 AI. I will acquire more. It might also be noted that current lots of Lapua 223 brass are 10 grains lighter (with 2.1 grains more capacity) than the brass I used in this test.”