I picked up a nice pre-64 Winchester Model 70 that's been rechambered from 22 Hornet to K222 Kilbourn. From my research, it appears to be a standard 222 Remington with the shoulder bumped forward to about 40 degrees and a straight tapered case, similar to the Ackley Improved wildcats. I loaded up some 222 Rem cases and fire-formed about a dozen rounds using 45 and 52 grain bullets. With the 1-16 twist barrel it did not like the 52 gr HPBTs at all. They were key holing at 50 yards, but it grouped decently with the 45 gr Hornet bullets. I don't have dies so I need to cobble together a set to neck size the fired cases and seat bullets. I have a Lyman 310 222Rem seater that looks like it will work once I can find a sizing set up. None of my 223 dies will work because the body taper is too wide. A 22-250 die might work if I shortened it up. I'd like to try a Lee 222 Rem collet sizing die if I can find one, but I don't know if the case body will fit. Any other ideas?