Ruger 77 MK-II 2223 twist?
Start a tight patch; being sure the jag is tight on the rod.
Mark the rod with a felt tip to indicate Top Dead Center and a starting point.
Advance the rod until it comes back to Top Dead Center.
Measure the distance traveled from the start mark. That is the rifling twist, one turn in xx inches.
A lot easier than trying to estimate the amount of twist in a foot.
Ruger 77 MK-II 2223 twist?
I had the same trouble with an Ultra-Lite that would not shoot.
Ruger said it was 1 in 10. Others said 1 in 7. I tried the above and it turned out to have a 1 in 12 twist.