is any one shooting a fast twist in a 22-250? been thinking about doing a re barreling and trying the 75 gr. a max's or 80 gr. sierra's at long distances. is there any data available on b.c on these two bullets?

Sierras are at www.sierrabullets.com/bullets/searchbc.cfm Berger bullets has a site too with a lot of data including twist suggestions. I did not just look to see if they make a long .224 but they must.

You have the right idea to use a standard case. I designed a short, fat .224 and the case prep while fun at first is just a problem now.

If I had it to do over I would select a 1-8 twist and the .220 Swift case.

FYI Winchester is coming out with a short, fat, short mag in ,224. Will be interesting.