bullet seating confusion

[navdoc]

I've been reloading for a year now for my old winchester 670 30-06.  I've been seating my speer bullets to the listed COAL in the RCBS manual for the IMR 4350 pwdr.  I finally just bought a hornady depth gauge and a comparitor set.  Here's my confusion: When I measure with the gauge set, it appears the bullets should've been seated much shorter than I've been shooting.  in fact, I can't even push the bullet in far enough to match the length of my previous loads, or even factory ammo.  If I try to push them in that far, the bullet gets stuck and I have to push it out with a ramrod.  Even more odd, I've been able to chamber the previous ammo.  Using the same bullets the whole time: speer 180 grain.  Any thoughts or advice from the loaders out there would be greatly appreciated.

[BOWHUNTER45]

I am a little lost on what your saying ...You say when you seat the bullet in a little further the bullet gets stuck in the barrel ?

[JLS]

I'm going to make a WAG here and assume that he means he has been seating them too deep according to his new set, and now they are getting stuck in the lands? 

If that's the case, it doesn't matter what any guage tells you.  Seat your bullets off of the lands.

If I made a wrong WAG, please clarify.

[navdoc]

What's happening is that the gauge procedure ends up with a much shorter COAL.  It's quit a bit shorter than the listed COAL in the RCBS manual (the lengths I was previously shooting).  What doesn't make sense to me is why was I able to chamber the longer rounds previously.   I'm thinking I'll make a couple of cartridges based on 0.020 off the hornady measurement and see how they shoot.  Will most likely need to back down on pwdr load as the bullet will be seated significantly farther into the case than previously.

[MuleDeerCrazy]

Sounds like you were either forcing the bullet into the lands when you close the action or the lands were shoving your bullet deeper, C.O.L. is usually shorter than that though.  Either way, I'd go with the comparator and reseat your bullets off the measured length, minus a thousandth.

On a side note, you should be able to chamber an old round and then unchamber it and either see lands marks or find your bullet pulled out and stuck in the barrel.

And if you change the seating depth, you will likely need to readjust your load as well.

[elkinrutdrivemenuts]

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?

[grundy53]

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...

[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!

[JLS]

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?

That would definitely explain the problem!

[cwuwildcat]

You probably know this, but you're going to get a lot higher pressures with seating the bullet deeper than the published COAL.

[Wazukie]

I would think, and this is what I go by, that bullet design along with chamber design has a lot to do with what your OAL will be.  I know that in my WSM and my .243AI that each bullet design, in the same weight, have different COAL's.  Just a thought.  I've never used the tools to measure, I have always used the old fashion way.

[BOWHUNTER45]

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 

[Heredoggydoggy]

You probably know this, but you're going to get a lot higher pressures with seating the bullet deeper than the published COAL.

Not as high as if the bullet is touching the bore.  The fact that the bullet has to "jump" a bit to get into the rifling has a lot to do with the pressure being within acceptable levels.  You run the risk of getting a bulged chamber if pressures are too high.

[JLS]

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.

[BOWHUNTER45]

Yeah its all trail and error 

[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.