I have a Winchester M70 featherweight in .223 Remington, how can I find what the twist rate of the barrel is? My best guess is it is an '89 or '90 vintage....any help will be greatly appreciated.

use a patch on a cleaning rod and measure the distance it takes to make one turn.

My M-70 in 223 is 1-12"

Sierra Suite lists both 9 & 12 with no further clarification. Best to check it yourself.

Thanks, I will check it myself. One or two marks on my cleaning rod with a sharpie should be easy enough...never thought of that!
I just got off the phone with Winchester/Browning, and the gal was able to tell me the rifle was manufactured in 1990, but was not sure on the twist.

Rayderluvr,

Your 223 of that vintage will have the 1-12". It wasn't until a few years later that they put the 1-9" on the varmint rifles, the Featherweight still used the 1-12". I don't remember when or if they ever changer the Featherweight.

Headache

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.