Every throat is different - measure it yourself on your gun. Take an unprimed case seat a bullet long in the case with no powder and no primer. Take a magic marker and blacken the bullet, load it by hand into the chamber and not through the magazine in a bolt rifle and close the action. Remove and measure. Then seat a 20 thousands deeper so that the bullet doesn't touch the lands and be happy. NO tools required. Most of us feed these through the magazine though so you still have to verify that this length will feed through the magazine. You can do this today with no tools and KNOW what your rifle needs.
You can also buy a couple of tools to make the job easier:
