A tool that will determine the Maximum COL for your firearms. This tool will work on any rifle. This one tool will work in bolt actions, pump guns, single shots, lever actions. It does not use modified cases and there are no parts to buy later when you change guns or calibers. It will work in calibers from .20 through .45 with accuracy as close .0001. Once you are familiar with it, you can find the MAX COL of the bullets you are wanting to shoot with in 1 minute.
This is the ultimate in a COL gauge, I love it.
You simply close the bolt, insert the rod from the muzzle, set the first stop, drop a bullet in the chamber and hold it in place, reinsert the rod and set the second stop, the space between the stops is your COL !!!
They sell these tools for $25.00.