That IS a bit pricey for just a necked up 223. Could just use a 257 neck/throat reamer with a standard 223 using a .257 bore sized bushing. If it weren't so high, I would be willing to pay them for their promotion of the cartridge anyway. But that's just too high for no more than it is.

I can see a bit of experimenting is going to take place on my part anyway. See if it'll match the 6x45 in an AR. My guess is it will and then some.

It's going to be similar to the TCU stuff back in the day of the Contender pistols except you're limited to 2.26 AOL.