Originally Posted by stvnbrg
so im wondering why almost everyone chambering a 22-250 and .204 offers such slow twist rates! The only thing i can think of is it wears the barrel faster with high velocity. Can anyone shed some light on this?? Other than that im sold on the cartridges especially the .204!
a lot of 22-250's were built (or are built) with a 1:14 twist barrel. Sounds slow, but you gotta be looking at the bullets most folks are thinking about using. That would be 45 thru 55 grain bullets. Most all bullets in this range work well in a 14 twist barrel (but not all). Savage went with a 1:12 twist barrel and it will shoot most anything upto a 60 grain bullet pretty well. But as time went by we started seeing heavier and longer 22 bullets being built that have a much higher B/C requiring a faster twist rate. Now Remington and Savage offer a nine twist rate barrel. The downside of this is that the fast twist barrels tend to over stabalize bullets that have lower B/C's. A .0001" error in the C/G of a bullet will give you a .093" spead at 100 yards, and the faster you spin them the greater the spread.
Actually the slower twist rates are prefered for group size if the bullet will stabalize of course. An example would be the 30BR with bullets around 115 grains. Guys using them in varmit for score competition often use twist rates as slow as 1:17 and 1:18. There's also the theory that the faster twist rates tend to foul a little quicker, but you can't prove that by me as I see little difference. Another good example is with the 6mm's used in target shooting most everybody is using a 1:14 twist barrel with bullets in the 70 grain area or slightly smaller. But you also must keep in mind they are usually shooting 300 yards or less.