I would be concerned if the manuals state 2.13, and you can't get below 2.18...
What Brian said above is absolutely correct. "OAL" is a rough guide- usually on the "safe" side- and should be OK with most bullets.
But as he stated, every rifle's chamber and freebore is different, as is the ogive on the bullets you might use and thus, the seating depth you can achieve.
Given that you can't get whatever bullet you're trying to load seated far enough to achieve "book" maximum, I'd proceed cautiously.
NO reason anyone that handloads (unless they're restricted by mag length and know they've got a ton of jump) shouldn't have a bullet comparator- or at least a modified case.
Order the Hornady LNL gauge, or you can make your own by slotting the case neck...but you need to make sure you're not jamming the bullet into the lands.
I could tell you a story from a couple of months ago when I started working up loads for my son's new K-31 and the modified case had not arrived yet...the manual OAL for the 7.5 x 55 is apparently based on other Swiss rifles with completely different chambers...
As we found out when, after about a half dozen rounds downrange he called me over to his bench. Couldn't get the bolt to close without a lot of effort...darndest thing... I told him to park it and shoot another rifle until we could figure it out rather than risk an out-of-battery disaster.
When the modified case came, I chucked the SMK into it and placed it in the chamber- the loads we were shooting based "on the manual" were a full 1/4" too long. That's a MILE in this context. He was jamming the bullet into the rifling that much; don't ask me how it shot so accurately, not to mention no "kaboom" from the obviously increased pressures.
Bullet comparators are too cheap not to have one- not only from a safety perspective, but also just knowing exactly what's going on in your chamber. Even bullets of the same weight, and different ogives, can have huge seating depth variations...
But that's yet another story.