I have found numerous postings on the "best way to check OAL" Some have cut slits in cases measure with a cleaning rod... ETC This was my method last night, I took a Sized and De-Primed Case. I filed the inside of the case with a chainsaw file till I could get a bullet to slide in and out barehanded. I then used my crimp die to tighten it to my liking. Then I placed a bullet in the case at its longest possible length to still sit square, I tipped my rifle toward the ground dropped the assembled round in. Cycled the bolt and pulled, out a set to max length round. When I pulled the round out I carefully held the round straight as my ejector puts a lot of side pressure and was pushing the bullet out of square. Depending on the Bullet My OAL was between 2.722 and 2.709 I did each bullet 3 times to make sure I was actually true, and I did have to tightened the case a little after 3-4 tries to keep the round from sticking in the rifling. I wrote the Maximum length of the round on the box of each type of bullet. I put the "shaved case" on a shelf with sharpie to use it everytime I get a new slug to try. Any other methods out there this took about 30 mintues to check 5 different types of bullets including making the case.