30-06 twist: 10" or 12"?

[lgm270]

For as long as I can remember, 30-06 rifles had 10" twists and .308 win's had 12 " twist.  Conventional wisdom was that the 12" twist would not stablize 200+ grain bullets. 

I've been lookign at the CZ 550 American but noticed that the 30-06 chambering has a 12" twist. 

Has anyone had any experience using heavy (i.e. 200+ grain bullets) in the 30-06 or 300  Mags?

The CZ action is a "long" action, that is even the 30-06 is long enough for 375   H&H  mag rounds. Howa and Remington also have magnum length actions.  The advantage is that you can seat 200 grain Nosler partition bullets with the bullet's base flush with the case neck and I have seen reported  MV's of 2,780 fps from a 22"  long throated 30-06 barrel.  IT was called the 30-06 long throat.   

I'm intererested in "long throating" a CZ 550, but am concerned about the 12" twist.  Does anyone have any thoughts, impressions, opinions, experience in this regard?

[Zachary]

You are correct, the heavier (longer) the bullet, the better it is to have a faster rate of twist.  In this regard, a 1 in 10 is better than a 1 in 12 when using 200+ grain bullets in .30 caliber.  Granted, I do not use 200+ grain bullets in any of my .30s - even the .300 Win Mag.  Only once did I use 220 grain Remington core-lokts in my .30-06 many years ago when I was just about 16 years old.  Best I can recall, the groups were not as good as the 180 grain bullets, and the rifle - my dad's Remington 700 BDL - has a 1 in 10 rate of twist.

Zachary