bullet seating confusion

[Fl0und3rz]

The gauge, if its similar to mine measures off the ogive of the bullet and not the tip. That could be why the coal seems shorter?

Using the bullet comparator is going to give you a shorter reading. What you need to do is take the comparator off the caliper measure a round with your wanted oal then put the comparator back on and see what that reads. The new "shorter" reading is what you want to go by. It is actually the exact same length, you are just measuring from the ogive instead of the tip...

This.  You cannot compare measurements such as COAL that are taken at the tip of the bullet with ones that are taken at the ogive, such as given by the comparator.  If you take the ogive measurements, then set your seating die up to 1-2 thousands off (bullet seated deeper) to ensure the bullet does not touch the lands, again, using these ogive measurements as a check on seating die set up, you should find that a tip-based COAL on a finished new round is in the neighborhood of your old rounds.  I would expect the ogive-based developed rounds would be longer, not shorter.   

As a check, use the comparator on the old rounds and compare this measurement to the new rounds.  As said, the new rounds should be longer, and if you are using everything correctly, I would expect the newer rounds to be longer, but not drastically so.

You said:

What doesn't make sense to me is why was I able to chamber the longer rounds previously.

This doesn't make sense to me either.  As I said, I'd expect your ogive-based rounds to be longer than any tip-based book COAL rounds.  In any event, I would not expect shorter rounds to stick, when longer rounds do not, if we are talking an apples to apples comparison of measurement (either tip or ogive).

Other things that remain unsaid are that we are assuming you are using the same bullets between old and new. Lot to lot variance should not be causing too much difference, but one type of bullet to the next definitely can.  Another point is that if you are using a digital caliper, I believe you have to zero the caliper once you have the cartridge comparator on.  If using an analog caliper, there can be some math involved.  Lastly, ensure you are using the proper comparator insert for the caliber.

[Heredoggydoggy]

COL in the reloading data is measured to the TIP of the bullet.  If a bullet is getting stuck in the barrel, it's just a matter of seating the bullet deeper so it can't touch the rifling.  I've never used one of those Hornady Comparators, so I know nothing about them.  Heard that they are good, though.  Technology is great, but old-fashioned horse-sense is better!

Totally agree  Just remember the COL in any reloading manual is for the safety of all users ...So they make sure their butts are covered for all users ...we all know what we can do to make our guns shoot better by seating the ball deeper or putting it closer to the lands ..that why we reload ...another thing you can do is take a a dummy load ( NO POWDER ) in the casing and take a black marker and mark the tip area in black and then slowly insert it into the chamber ...if it feels like you are forcing the bullet into the chamber go ahead and eject the casing to see if you have rifling marks on the tip of the bullet ...if you do then it is to close to the lands ...I would seat it another couple thousands and repeat the process until you have no marking on the bullet ..once I have no markings on the bullet I then seat it another 1 to 2 thousands to be safe ... someone correct me if I am wrong 

That's the tried and true process, however I usually have to seat them deeper to fit the magazine box on my M70's.

That's a fact--on some rifles, COL is dictated by what fits in the magazine.  AR 15's are a prime example of that! 

[navdoc]

Thanks all for the input.  I'm going to re-measure with the hornady tool and set my next depths based upon that data.  Hope to report good success after my next range day.

[mazama]

If it fits in magazine it should be fine,i seat all oh mine to fit overall length of magazinne,B arnes bullets are long for weight,they are the ones that may have to be deep seated.

[NRA4LIFE]

I do exactly what Bowhunter45 described.  I have found my most accurate rounds are where the bullet is as close to touching the rifling as possible.  I only can do this with my bolt actions.  My one auto would not feed properly with the bullets out that far.  Had to try multiple depths until it fed properly.

[h20hunter]

I am 100% with Bowhunter on the dummy round. Part of the process I go through in setting up the press and creating the current load is making dummy rounds. I usually end up with a handfull that have no powder/primer. For me it helps on pretty much eliminating the need to knock apart rounds that wont chamber.