7mm Rem mag ...OAL concern

So I was starting to load up.some 7mm Remmag using Speer 140gr Sp (1629)
Just for giggles I broke out my Hornady Lock n load Oal.gauge. I checked my bullet and came up with a max OAL of 3.250 in my Weatherby Vangaurd.
The Lyman manual lists 3.29 as max Speer lists 3.28 max OAL.
I double checked my Weatherby again to.confirm and got 3.25 again.
I checked some new Remington and it measured 3.2
I will go with my measurement but wonder why the big difference?

Weatherby's always have a lot of free-bore. In a 7 mag you can probably load a bullet long enough to get there, but typically it's tough to chase the lands on a Weatherby. OAL is just a number. As long as you've got enough bullet left in the case neck, and it still fits in the magazine box you can load it as long as you like.

That's the thing .. Don't believe the non Weatherby cals have the freebore

All rifles have freebore. Some have more than others. Just measure your OAL in your chamber and go back .010 and play with seating depth to find the sweet spot.

Yep. 7 mags are notorious for having unpredictable throat lengths. Measure for whatever bullet you want to use and seat accordingly.

From the Weatherby FAQ on Weatherby's site:
What is the throat length (free bore) on your Weatherby rifles chambered for Weatherby magnum calibers?
Cartridge Throat length (free bore)
.224 Weatherby Magnum .162
.240 Weatherby Magnum .169
.257 Weatherby Magnum .378
.270 Weatherby Magnum .378
7MM Weatherby Magnum .378
.300 Weatherby Magnum .361
.340 Weatherby Magnum .373
.375 Weatherby Magnum .373
.378 Weatherby Magnum .756
.416 Weatherby Magnum .239
.460 Weatherby Magnum .756
.30-378 Weatherby Magnum .361
.338-378 Weatherby Magnum .361

Good info ....except mine is a 7mm Rem Mag