Re: figuring out rifle twist
This is how I check all my bolt actions.
I use a black coated Dewey cleaing rod with a nylon brush (2 sizes below caliber of rifle) attached and then wrap an appropriate sized patch around the brush.
Remove the bolt and start the rod with brush/patch. Once it's just inside the chamber I use WhiteOut and place a small dot on the top of the rod. This dot should be aligned with the back edge of the recoil pad (I eyeball it).
Once the WhiteOut dries, slowly push the cleaning rod down the barrel and rod should rotate. Keep an eye on it as you push and once the dot is top dead center again, wallah, you have one complete revolution.
Now measure from the white dot to the recoil pad and you have your barrel's rate of twist. Repeat if necessary. Johnny K.