I googled 22-250 barrel twist and had plenty of info to read. I believe I have 2 choices.
#1 Stay with 14 twist and 55 g. vmax bullets, which has proven to do everything I need to 400 yds. with decent barrel life.
#2 Go with a 8 or 9 twist and shoot something like a 75 g. vmax and extend the range but with shorter barrel life. Also not as flat out to 400 yds.
Remember this is a walking rifle for called in coyotes. When its bellow 0 deg. and I'm dressed like an eskimo wearing snowshoes I don't want to carry a rifle built for 1000 yd shooting.
As I stated earlier you can still use 55grainers in a 9 twist and not hurt the barrel anymore than a 14, the throat is always the first to go not the rest of the barrel, and that gives you options for heavier rounds if you may need them, I run 40s through a 12 at 4220 and it doesn't hurt it, when the throat starts going start chasing it out with your seating depth.
*in a 14 twist barrel the v-max seems to be about right for it's twist. But on the otherhand a 50 grain bullet from Nosler will work as well. Most all 60 grain bullets are out of the equation as they are too long for the slower twist.
*in a 12 twist barrel the perfect bullet seems to be a Sierra #1365 (a lot of folks have came to this conclusion as well). But the 55 grain Hornaday and Nosler BT works very well. The faster twist will do some 60 grain bullets to a certain extent; with the 60 grain Partition being one of the best. The 60 grain Hornaday will work as well, but not quite as well as the Nosler due to a lower B/C on the Nosler. Yet the 12 twist will also do 45 and 50 grain bullets just fine.
* a nine twist should do about anything, but groups will open up with lighter weight bullets due to over stabalization. If I were using a nine twist barrel, I'd be using 60 grain and longer bullets
i did my 22-250 in 9 twist. do yourself a favor and do the same. you can stretch that guns legs and see the 22-250's true potential. shooting a 60-75 grain bullet in these allows great long range capability but still delivers excellent short range results. i feel its better to be able to shoot long even if you don't because there will come a time when you will want to. my gun shoots in the .3's and 4's at 100 and just about .5-.6 moa at 800. its by far a true custom but it is a very good shooter for my first long range build.
edit: as for the "flatness" of traj at 400 yards it drops 3.5 moa at 60 degrees F with a 200 yard zero and 17.5 at 800.