They could work.
According to the Miller stability factor [if I figured the correct bullet length] @ 3500fps the stability number is 1.043 for a 65gr Sierra with 12 twist. This is marginal, but I shoot some other bullet, barrel combinations that have a stabilization number in the high .900, and they group well.
Stabilization numbers should be in the 1.30 range and up for good stability.
Give it a whirl!