There are three ways to get a good measurement on OAL in your gun.
The easiest and most accurate way is to get a Hornady OAL gauge and modified case. If you get one, post here and we'll explain how to use it correctly, as the instructions are somewhat lacking.
The second way, which kind of requires 3 hands, is to use a small rod, like from a cleaning kit, to very gently press a bullet into the chamber until in touches the rifling. Then, slide another flat ended rod (a wooden dowel of appropriate size works really well) down the muzzle until it touches the bullet and use a razor blade to mark the rod at the muzzle. Now, remove the bullet from the chamber and close the action. Slide the rod in the muzzle down until it stops on the breach-face. Mark it with the razor at the muzzle again. The distance between the two marks is the OAL that will touch the rifling with that bullet.
The third way is to use a fired case and size the neck ever so slightly until you can just seat a bullet by hand and it will stay in place. Leave the bullet out extra long, just barely in the case. Now close this round in your gun and extract it slowly and carefully, catch it so it doesn't go flying and change the measurement. Measure this round and repeat this procedure several times. I do it with a couple different bullets and cases to get a decent reading. I also rechamber the round several times to make sure that the length doesn't change slightly every time it's done because the bullet sticks in the rifling and pulls out of the case slightly.
Personally, I had some trouble getting good results with 2 and 3 until I figured out the techniques. It works pretty well now.
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.