bullets / oal

[robert j]

I know why they give a over all length for cartridges. but why not on bullets . I made my own comparator for seating my bullets to the oal . but to obtain the over all base to the ogive I first have to find a bullet that's not deformed at the tip or the meplat. then set to the over all length in the reloading book and then use the comparator to set the rest of the bullets in my reloading process . has any body run across this before I found a Berger add for some plastic tipped bullets that had there oal listed but not in there reloading literature. same for speer ,hornidy lymad ect.

 

[Mikecr]

I think you're confused on the terms related.
There is:
-Cartridge overall length (OAL, case head to bullet tip)
-Cartridge base to ogive (CBTO, case head to a bullet nose datum behind the tip/near land contact point)
-Same lengths for bullets alone

OAL is truly meaningless to anyone.
CBTO is very meaningful while you make it so (through testing).
The bullet parameters are mostly meaningless to CBTO, as CBTO is set with your die and verified correct (by you) regardless of bullet.

It's pretty standard in reloading to test for best bullet seating depth, measured as CBTO, adjusting the seating die to reproduce this, and never changing this for the life of the barrel.

 

[FEENIX]

I know why they give a over all length for cartridges. but why not on bullets . I made my own comparator for seating my bullets to the oal . but to obtain the over all base to the ogive I first have to find a bullet that's not deformed at the tip or the meplat. then set to the over all length in the reloading book and then use the comparator to set the rest of the bullets in my reloading process . has any body run across this before I found a Berger add for some plastic tipped bullets that had there oal listed but not in there reloading literature. same for speer ,hornidy lymad ect.

Berger has an excellent article on COAL vs CBTO that is worth your time to read up on.

Good luck!

 

[robert j]

I have read the Berger article and it makes sense . but what I am after is consistency in my bullet seating depth . it is hard with the bullets all smashed at the end . I do realize that once you set your depth they all should be the same because the die is pushing on the ogive and not the tip . but I like the hornidy comparator because it to is measuring from the same ogive .that's why I made my own . so it does not matter that the tips are smashed . but I will know that they are all seating to the same depth . not every one reloads to the rifling . maybe the bullet oal does not matter .

 

[barefooter56]

I have read the Berger article and it makes sense . but what I am after is consistency in my bullet seating depth . it is hard with the bullets all smashed at the end . I do realize that once you set your depth they all should be the same because the die is pushing on the ogive and not the tip . but I like the hornidy comparator because it to is measuring from the same ogive .that's why I made my own . so it does not matter that the tips are smashed . but I will know that they are all seating to the same depth . not every one reloads to the rifling . maybe the bullet oal does not matter .

Robert,
Does your seating die have a seater stem that works with our VLD bullets? You mention "smashed" tips. If the tip of the bullet is bottoming out in the seater stem this can cause big swings in seating depth variation.

 

[robert j]

no they come from the factory that way. not all of them . the reason I posted. was that every time I would Google on different ways of using the comparator. it would come up with seating to the lands or just off them by 20/30 thousands. I am not sure about the seating stem but I be leave that it presses on the ogive. 2 sets of dies using the rcbs and have a Lyman set .thank you to all that have replyed .

 

[Corey Schwanz]

Don't measure to the tip at all. Use a comparator to measure off the ogive instead. Its a much more accurate and consistent measurement point.

There are a variety of ways/tools to find what length of loaded round you need to touch the rifling. Once you have established where your rifling is, measure a dummy round with your comparator of choice and that's your baseline. Then, just make sure to always use the same comparator when checking for OAL and adjust your die until you get what you want for actual depth.

If you are loading mag length instead of way out, just adjust your die further down until the loaded rounds fit your magazine. Then measure those with the same comparator as a "mag length baseline" measurement.

Bullet tip lengths will vary in almost any brand of bullets you shoot, and in most cases, really isn't that important of a measurement point.

 

[barefooter56]

no they come from the factory that way. not all of them . the reason I posted. was that every time I would Google on different ways of using the comparator. it would come up with seating to the lands or just off them by 20/30 thousands. I am not sure about the seating stem but I be leave that it presses on the ogive. 2 sets of dies using the rcbs and have a Lyman set .thank you to all that have replyed .

RobertJ,
Neither of those die sets have seating dies with a VLD seating stem. RCBS will make you one. Lyman I dont know if they will or not. Better check if the tips are bottoming out on both sets.