Twist rate for Ruger 30-06 in past

[LouB]

I know that current Ruger model 77 's in 30-06 are currently 1:10 twist rate.  Did Ruger ever produce them in 1:12 twist rate.  I have a friend whose rifle shoots 150 gr bullets well but as bullet weight goes up accuracy fails ... 180 gr and above are terrible.

Comments  ... Information?

Thanks,
Lou