Does anyone have any idea why there seams to be little published load Data. I have never shot the 223 WSSM is there a reason for it's lack of popularity. Everything I have seen says it's faster with better accuracy than the 220 swift or the 22-250.
Dr B

The only thing I know about the 223WSSM is that the short, fat cartridge has (or had) feeding problems. That was enough to put me off of it.

I've read that the pressures created by the short fat case are intense and come on much, much faster than standard cases, Hornady manual for one.
I've read, unofficially, that it does not compete or even approach the other fast 22's in terms of accuracy.