"Not hard to measure it yourself."
This^^^
Take a cleaning rod and a 7mm bore-brush. Wrap the brush in a cleaning patch or two, enough to require a little effort to push the brush down the bore a little ways. Mark the cleaning rod by putting a wrap of masking tape just in front of the rod's handle, and mark it with a "reference point" with a ball-point pen.
Measure the distance from the mark to the recoil pad/buttplate, then push the rod into the bore until the rod twists until the reference point is in the same postion. Measure the distance the rod has traveled, and that's the rifling twist.
Repeat if you're not sure about the first measurement.
