I use a cleaning rod with a tight patch. it must have bearings in the handle to allow the rod to turn, following the rifling. Start your cleaning rod into the lands from the breach end, as soon as it is fully engaged in the rifling, mark the rod with tape even with the back of the action, now place a dot on the rod in front of the handle faceing straight up. Start your rod moving through the barrel and observe the dot rotating, when it is again located straight up, mark the location at the back of the action. measure the distance between the two marks and you have the twist rate. one turn in "X" inchs.