I have a test target from Savage, on a gun that they sent me, a 10 Percision carbine, in 1in 9 twist that they used Federal gold match ammo loaded with 77gr Sierra Match King bullets. I am sure if the bullet would not work Savage would not use it to test a rifle. I bought a box of them, and they shot very well out of that same gun, actualy it was one of the best shooting bullets I found.

Now a bit of information on the Sierra 77gr bullets, I talked to Rich Machholz (Bulletsmith at Sierra.) last week at the IBS 600 Nationals he told me that this bullet is considered a special bullet, that is why it comes in boxes of 50 instead of 100. The bullet was designed for AR15 rifles, they never intended it to be used in a bolt gun. (This is why you will not find loading data for it in Sierra manual except for a AR15, and Sierra's test rifle is a 1 in 7.) The reason why it is considered a special bullet is because they have to keep closer tolerances on the bullet to ensure that it will fit , and function in a magazine.
Now with that all said, the lable on the box says for 7-8 twist barrel only.