What he said, except the obvious...
I have a 1-9, but would do a 1-8 every time over the 1-9; I've never had issues with the 75 A-Max shooting great, but would hedge even more.
At the time, I barreled it for 69 grainers.
Sako used a 1-12 on their .223's and 222 Mags, not that it gains anything over a 1-14. Remington used the 1-14.
I didn't know that about Sakos...and I have noticed a difference between the 1 in 12 and the 1 in 14....
Likewise the 1 in 10 I mentioned that I loved was built with 68 and 69 grainers in mind....which it shoots well indeed.
But again...the 1 in 8 digests everything I put in it.....
