Well I got around to loading and shooting some fireformed brass for my 223 Ackley "Walk Around Varminter" (www.rvbprecision.com in the photo album). Here are some observations. With a 50grain Nosler Ballistic Tip bullet and 27 grains of Vit133 the bolt lift is hartd and the primers are cratered. This is with Remington nickle plated brass. What is interesting is if I use Winchester headstamped military brass I get extremely hard bolt lift. Why this is interesting is that the Winchester brass has more internal volume than the Remington (Rem brass holds 30.5 grains of water and the Win brass holds 31.8) You would think the Rem brass would show much more pressure. Comments?
While I was fooling around with internal volume, I measured some other cartridges for comparison.
222 Mag = 31.6 grains of water
223 Ackley = 31
223 = 30
22 PPC = 31.1
22BR = 37.9

As you can see, there is very little "improvement" frm the standard 223 to the Ackley. It would appear to me that the 222 Mag would be the idea cartridge. You could simply run a 223 Ackley Reamer into any 223 chambered rifle without setting the barrel back and Im guessing the "improvement" would be about 12%. I have a 223 Contender barrel that Mike Belm chambered for me in 222 Mag Ackley, but I've never shot it. Guess I'll have to do this and see how it works out. I see an order for a 222 Mag Ackley reamer in my future....
My load development is going as follows. So far I've only used 40 and 50 grain Noslers. I always use moly in varmint (high rate of fire) guns. With any load I've tried the gun is shooting under a half inch. (love those Pac Nor barrels!)
My best groups so far are with 40 gr and 27.5 of vit 133 for a speed of 3700 fps and an SD of 6. Groups averaged in the 3s. Although this is great. I expected to be approaching the 3900 fps mark. I can get 3700 with a 40 grain moly bullet out of my standard 223s.
I found 50 grain bullets work much better with the slower Vit 135. 27grains of Vit 135 under a 50g NBT gives me 3400 fps. The average group is in the high 4s. Again, not bad, but not worth the extra work of the Ackley fireforming and rechambering.
So where does this leave me. Trying more bullets and a few more powders to see if I can edge the velocity up a bit without pressure issues.
Any comments?

You should talk to Genghis about the 223AI. He thinks its the greatest thing since the poptop .Seriously, I think he has played with this round to great extent.

RVB - As you have just figured out, the 223 AI is a waste of time. Ackley was a strange sort of fellow and always told the truth of what he thought of firearms. In his books, he readily admits to designing a lot of "WORTHLESS" cartridges. (His exact word) He didn't do it because he didn't know any better but because someone paid him to build such and such. And since he was in the business, he built what they wanted.

One look at a regular 223 case should show us there is really nothing to "improve" about the thing to start with. The case already has a minimum body taper and barely enough neck to hold a bullet.......so the only thing to do is blow out the tiny little shoulder...which gains us SQUAT.

It's really a cosmetic wildcat. It LOOKS different, therefore it MUST BE different and BETTER. (But it ain't)

Personally I would never bother to "improve" any case that couldn't produce a hell of an change in case capacity and velocity etc. Not everything that says "progress" or "new and improved" is.

The good news is no real harm done, although there may be a down side when you go to sell or trade the rifle off.

You need to pay attention to those high pressure signs you are getting! I think because of the low recoil and soft voice of the little hot .22s, they are probably OVERLOADED more than anything. But you can wipe them out just the same as any rifle. Clearly you need to back off some of your loads and stay with what your rifle is comfortable handling. Forget what the books and others tell you and listen to your rifle. IT decides what is a good, comfortable load.

Anyhow, I wish you luck with your rifle. They are all fun to mess with. Enjoy.

P45

Pecos, thanks for the thoughts, but there are a bunch of folks that have been emailing me with their real world results that would differ with you greatly. Can you give me some information on the 223 Ackley you are shooting? It would really help in my quest.
Thanks

I am using a 223 AI in my Rem 700. With a 26" barrel I am getting over 4000 FPS with a 40g Vmax and under 1/2" from it. I am using 29g of AA2015 and IMI brass. Tried WIN and REM brass and did not have any good luck with it. This is from a factory barrel that was rechambered. Didn't want to eat up a premium barrel fireforming. Not sure about the 222Mag AI. I bet it would be a great performer also, but cost of 1000 brass would kill you. I used mine on PDs this year and it was much better than my 223. I got 3670 fps out of a 50 BK and very good visuals.

Mike

The main advantage to improving the .223 as I see it would be....less case triming. That's it, but handy for high volume shooters.

"Why this is interesting is that the Winchester brass has more internal volume than the Remington (Rem brass holds 30.5 grains of water and the Win brass holds 31.8) You would think the Rem brass would show much more pressure. Comments?"

The nickel plating is slicker and thus, doesn't grip the walls of the chamber as hard. (Some people even claim they don't need to use lube when resizing nickel brass!) However, if you are getting hard bolt lift with a case of smaller internal dimensions, you are WAY over-pressure with the Remington case.

[QUOTE]Originally posted by RVB:
I've got two 223AI and I average 3558fps with a 52 gr bullet and I average 150fps over my standard 223. Is it worth it for me it is, I gain alittle over 100 yds in the field when shooting pd. I think the 222Rem Mag AI would be worth trying and think my next project wll be that. I have a 222AI and it's a great round. Had it done with a 1/12 twist pac-nor barrel and set up for the 55gr bullets. I don't have any problems with my cases as I use a wilson and Neil Jones hand die. The 222AI was called a 222 1/2 and was a good BR round. Well good luck! Tom

i just had a 26" Lilja-barrelled 1:9 twist AR built up in the .223AI. It seems to shoot most bullet weights about 100-150+ f.p.s. faster than another friends 24" barrelled custom AR's. We started with AA2015, and stuck with it. I am starting to hunt coyotes by the spot and stalk approach, and intend to investigate the performance of the various "middleweights" (68 + 69's) by Si., Hor., Nosler, and Starke. I think I'll be able to hit 600 yds. with the help of tha various associated optical, and computer paraphernalia, but I,m a little concerned about bullet expansion beyond this distance with these target-type bullets. I don't want to pencil these dogs and not kill them outright. Oh, I almost forgot I'm getting 3270 f.p.s. m.v. out of them, but it's too hot (primer pockets expand after 3 reloadings, or so).

sorry about the last posting---make that powder AA2520. I guess I had a middle-aged moment.

sscoyote,welcome to the forums! Have you had any feed problems with your ar? Also were there any mag/feed ramp adjustments involved?Been very interested in doing this to one of my ar's. Clay.