I am trying to determine the freebore/lead in one of my rifles using the Hornady OAL gauge and Hornady bullet comparator. It is my first time using this kit.

From the base of the modified 30-06 brass to the ogive of the 208 ELD-X, I am getting an extreme spread from 2.600-2.750".
I tried a different rifle in .308 and was getting variations of 2.194-2.206" (base to ogive) with an 178 ELD-X. It wasn't a big deal since the bullets would load to long, regardless, due to magazine restrictions.

I was getting the same wide variations measuring from base of the brass to the tip of the bullets as well.

Anyone else have any tips on what I may be doing wrong here?

I am using an OriginCal Digital Caliper. "Bullet base to ogive" and "bullet to meplat" was measuring consistently +-0.0005".

In my own experience using this tool, it is common to find that bullets from any given lot of quality manufacturer's bullets will vary a total of about 0.010"(entire range, not +/-).  With bullets designed and engineered for precision, like the ELD, I would expect that to shrink even more.

I think what you are experiencing is common and I "think" I know exactly what you are having happen. It may be more prevalent with a less than clean chamber, maybe not.

When you get the modified case all the way into the chamber and start pushing the bullet with the wire, sometimes it gets a little "hung up" and seems to have stopped, but is not actually all the way to and touching the lands. Back off it a but and push it again. It could be dirt or a ever so slight rough spot that is stopping the bullet.

Pushing with that little wire, you will not physically be able to push hard enough on the bullet to mess up the measures by pushing the bullet into the lands. I will warn you that you will likely need to have a rod available to push the bullet out because it will stick to the lands. As long as you screw the wire stop down, that is not a problem. When you get the bullet out, just put it back in the case and measure. You should be very close on measures with all bullets tested.

Pro tip: use a bullet of a smaller caliber to make it faster popping that bullet out that is stuck in the rifling. Don't drop it straight down the bore vertically or you will mess up the bullet tip(and possibly your measures), but let it slide down at an angle.

Thanks, I will give it a try by pushing on the rod a bit harder to ensure it is touching the lands.

Bore should be pretty clean since it has less than 100 through the tube right now. Just fouling the bore and breaking it in.

I was only using 2 samples of the bullets, o I don't think it is a bullet to bullet variation. I would use the same bullet multiple times to take the measurement to rule out the bullet variations. Even still, I measured multiple bullets and they were fairly consistent. Within 0.001".

I had this probelm when i tried it on a dirty bote too. Didnt think about that till now. but what i did was tried to push it in there real snug, then subtract .001 and i got more consistant numbers
Didnt have this problem with bergers and a clean bore last time.