Base to Ogive.....

How do most measure this when using the Hornady OAL guage?.......Do you insert until you barely feel? I’ve found that there can be as much as .033 difference between when I can “barely feel” (inserting lightly until it stops and a couple very light taps to make sure I’m there) vs. inserting with just enough pressure that the bullet sticks, in my case 2.155 vs. 2.188. Also, does anyone make a bullet seater that seats using the ogive vs. the bullet tip? Thanks.

Most bullet seaters should touch closer to ogive than the actual tip of the bullet.
You can put a bullet with a mild abrasive like JB or Flitz in a chuck and polish out your seater cup to try and get closer I guess.

I stop the caliper when I feel it stop. Tapping the caliper might be seating the bullet deeper in the case.

If you're getting the ring around the bullets, Hornady and Redding make seating stems for the pointy high BC bullets, so that they don't damage the bullet while seating.

I use a VERY light touch when pushing the plunger in until I feel it first touch or meet any resistance (touching the lands). I put the plunger between index finger and thumb similar to holding a pencil and get very repeatable results. I take 3 readings per bullet and 5 separate bullets for a total of 15 measurements and take an average. I rarely have more than .002 delta between measurements.

Most die companies make a VLD bullet seater.

Well, using a very light touch. I just measured 15 bullets, threw out the 2 highest and 2 lowest and came up with an average of 2.1560.
( I’m doing this because my accuracy has degraded a bit, hopefully due to the barrel being broken in, just over 350 rounds)
I’m finding this strange because the initial loads (which shot fine) were 2.188 OBTO and .010 off the lands. Is this kind of change normal?

Time to scrub out the carbon ring, clean the whole barrel, then find lands again.

The smaller the bore, the larger the powder charge, the faster the throat erosion. 6mm Creedmoor is a pretty small bore, with quite a bit of powder. But I'm more leaning towards carbon ring. It's a scrub with a brush job, after soaking in a carbon remover.

Agree except I’ve cleaned the hell out of it with iosso, Butch’s and brushes. Wouldn’t throat erosion cause the distance to be longer?

Erosion would cause longer.

Two different calipers in question here as well. My analog and your digital.

Same here.

Clean your chamber as well as the barrel. Stand the rifle vertical on the buttstock to take your measurements. That should make the lands easier to feel. Effect of gravity on a long horizontal bullet in a loose neck can give a false measurement. Double check which bushing you are using as well. The next size smaller bushing will give a short measurement. As soon as your bullet touches the lands is the measurement you want.

besides a VLD seater, your neck tension could be too tight. Do you use and expander mandrel?

I have always used the long Hornady tool with a small dowel rod inserted through the muzzle till it touches the tip of the bullet, then go back and forth, very positive feeling of bullet touching and entering the lands.

The following is in response to your first question about the OAL gauage and how to use it. Disclaimer, it does not follow conventional norms on this forum.
I kinda hard shove my bullet in an attempt to find the hard jam point. In fact, it's only a reference to know what's the max and NOT go there. After that I do run a small seating depth test to see what depth it likes. Again this is not the "kiss your lands and back off xx" procedure. I mostly model this after the follow video.
https://youtu.be/obTvUY5LQ3A in about minute 12. And...
https://youtu.be/oRXlCG9YZbQ

I've tried other methods and found them VERY inconsistent. This is what I do now and have been supremely satisfied since. I've actually met Texas Precision at a local Houston f class match and can definitely say he can shoot.
FYI, I've been told this method leads to excessive throat erosion but I've not heard why.

Edit: i do definitely make sure to really clean the barrel before doing this. I have found that fouling will screw up the measurement.

I use this method often as I have 3 Switch barrel rifles and while it’s a little slower it very accurate.

https://youtu.be/cAVDu-4gLrk

I don't know about constantly taking off a barrel but...what a great technique. I may have to try it out. I'd like to buy a barrel for a new caliber by the end of the year. I may try this before installing it.
Thanks for the info.

I do the same method above, but with the rifle and chamber checking the round by closing the bolt. You can easily find the lands doing the same thing when chamber checking the round and looking for rifling marks. It take 3-4 rounds and several attempts to dial it in, but it works.

This plus you have a different ogive measurement tool and technique that could account for differences. The absolute measurement is not as critical as consistency in your measurement process and the ability to duplicate it. Watch a few Erik Cortina videos on "finding jam" and "chasing the lands". Scott Satterlee has a different take on jump to lands and seems to favor the .060 range.

Yeah it's one of the tougher things to get a feel for in my experience. I honestly probably measure 20 or 30 times until I get a feel for the amount of force required to get consistent results. Once I start getting the same answer within 2 or 3 thousandths for at least 5 measurements in a row. I usually start at .030 off the lands for ELD-M and adjust from there if necessary. I've found that .020 usually works a hair better in my experience.

I found this to be true. My rifles actually don’t mind if I set CBTO .001-.002 off from the distance I selected. My 7-08 die is a cheaper RCBS type with the nut and stem so I don’t always get the same exact length when loading.

Measuring my max OAL has solved accuracy and pressure problems. Mag length rounds in my 7-08 will smash the bullet into the lands which caused numerous overpressure incidents. Now, I haven’t had so much as an ejector swipe.

First off, many thanks for all the responses.....I finally took some measurements and found the biggest reason for the varied results is the bullets themselves (115 DTAC).... I found up to 0.015 differences in diameter thus not allowing them to fit into the comparator the same with each one. Mr. Stroud, I used your method by inserting the loaded round (sans powder) through the chamber and then turning the gun over to see if it would drop out freely. This gave me the best/most repeatable results. Again, thanks all!

???

What caliper?

As in bullet diameter? 0.015 goes from a .243 to bigger than a .257?

MY DTACs varied in length but never in diameter.

Just curious, did this turn out to be a mixed box of bullets?

This turned out to be a caliper problem. Inaccurate, cheap digital caliper.

And a finding rifling problem with the Hornady tool.

I loaded a piece of brass (cut neck) with one of Chris's bullets long, wrote it down, chambered it, wrote it down, repeat, repeat, repeat. Throat erosion is only .024" right now, after 350 rounds. I used an American Made Starrett analog caliper. Then used a second one of the same make and model. I have one for the loading bench, and one for the lathe. Both Starrett calipers gave exactly the same measurements to the thousandth.

Four bullets varied in length only .001", base to ogive, if memory serves.

Four bullets had no variance in diameter.

Thanks, I too like my analog caliper.

I need to get an analog caliper.

Yes you do.

There's something elegant about them. And I trust them more.

got one i could live without for the right price