I was just reading a little about it at the bookstore. A 125 gr. bullet, 0.226" in dia. running at 2700 fps out of a 1-in-5 twist barrel. Parent case was the .257 Roberts, I think. Wow!!! Has anyone had actual experience, or even second-hand knowledge of this cartridge? Why didn't it succeed? Who produced the unique bullets and barrels for the few guns made? Finally, was the bullet just a standard lead-copper deal, pure copper X-bullet, or some composite of tungsten perhaps? Any info is welcome. Thanks.

Geo,
Were you reading the P.O. Ackley books "Handbook for Shooters and Reloaders"?
That's pretty much the description from his books.
As to bullets, there were several individuals, Barnes, Clark and Sisk as well as one company, Hornady, that manufactured bullets in heavy weights for these hyper velocity cartridges. I have run across and purchased many boxes of the 80 and 85 grain Hornady and even managed to find one box of the Sisk bullets. These bullets were standard copper/lead manufacture. The equipment used to make them was standard also except that it was bigger (longer) to get the weight. Look at the 80 grain Sierra's to get an idea of the length. And before you ask, no Hornady will not be making any more of these bullets which were true .224 not the .226 that you are asking about. I called and talked to just about everyone that I could and the answer was consistent, "if you want to order 10,000 we will look into it". They were very nice but I suppose that all of us that have an interest in these things has called them at one time or another.
The reason it failed; .002" difference from the .224, who needs this configuration?
Yes, I shoot several variations on this concept:
- 22-6mm and 22-6mm Ackley Improved
- 5.6 x 57 (European hotrod) has a thicker
neck to allow the use of a 22 rimfire
adapter.
- 22-243 Ackley Improved
- 22-240 WBY.
- 22-350 Rem. Mag.
- 22 Easling (22-06)
and probably a couple more that I can't remember right now.
The best part of this is that there are the 80 grain Sierra and the 75 grain Hornady bullets that function and are available today.
If you want to pursue any of these, pick an easy one first and work your way up. Most of these except the Ackley Improved require brass forming and then fireforming in the chamber. Ackley's can be fireformed in the chamber from factory standard cartridges.
Bill