Ogive measurement

[Ceefuhs]

Once you measure the space from the bottom of the cartridge to the ogive for one bullet type should that be a constant for any other bullet?

I am confusing myself.

Thanks,
Seth

[Cover Dog]

No, bullets have different shapes and the ogive will differ from one bullet maker to the next. You might find one or two that are very close to the same measurement, but you can't just use one measurement for all bullets.

[Quickshot]

Looks like no one wants to chime in, I will. Absolutely not. Each type of bullet that you change to will need to be rechecked as they almost always will have a different configuration. Not just bullets from another manufacturer but any change ie: hp.fmj, rn, sp or other. If you are not caerful with this process you could jam one in and end up with a mess. Good luck, Quick

[Ceefuhs]

Thanks guys. Now I know I am not going crazy ... crazier.


Seth

[Nor Cal Mikie]

What I do is measure each different bullet brand and design that I plan to load with. Measurement is too the lands. Write them all down. That way I have a chart to refer to when I set the OAL. (to the lands)
And if you do a "lot" of shooting, go back and measure again after a couple of hundred rounds. That first measurement (to the lands) "will" change.

[lal357]

what they said i got into the habit of measuring for each box of bullets and as i pm'd you i sort the wholle box by ogive my reloading desk is slamfull of ziplock bags right now from 75 gr amax ,69gr smk and 75gr hornady match heads that i did a few days ago.

[L.H. Clark]

I'm with NorCalMike on this one. I usually use several different weights and brands of bullets in any given caliber. I like to take the Hornady comparator and measure the box of bullets from base to ogive. That gives me an idea of the consistency of the batch. I then decide which brass I'm going to use and get an C.O.A.L. with that particular bullet/brass combo. I then write down the "To the Lands" distance in the top of the box of bullets with whatever brass I'm using. I then write it down in my rifle/caliber specific log/load data book and then I've always got a record so I don't have to go back through all that again. Except of course for measuring specific lots of bullets, but that, usually, won't be too different with same weight/manufacturer/type. They are pretty consistent, lot to lot, anymore. Technology has sure made life a lot easier for handloaders!

But to answer your question, every different weight, material, configuration of bullet will be different from base to ogive.......

L.H. Clark

[Nor Cal Mikie]

Something that Mr. Clark mentioned that I "don't do" is measure each bullet in a box. As far as being consistant? You would think so but I've seen mixed batches of Bergers of one weight. Could happen to anyone. Berger made them good. Got a couple more boxes from them that were spot on. ;) Sure wouldn't hurt to check a few from time to time. Make sure to keep lots of notes to look back on.

[gotcha]

Norcals advise is "spot on". Good notes are the secret of consistantly accurate reloading results. Lands to base measurement lengthened on my .223 by .005" after a PD safari. Tho' the rifle was still shooting well, adding .005" to the COAL tightened the groups back to size of original test groups. Dale

[Nor Cal Mikie]

Do as I say, not as I do. :-[ I keep "very few" notes except my OAL to lands measurements and a few targets with powder charges for the best group.
My shooting buddy has notes that go back "years". He can tell you how long, how much powder, how hot or cool it was, wind or not and how much time we had to BS.
Me on the other hand will be burning off 200 rounds out of my M1A while he is taking notes. We make a good team. ;D

[GaCop]

I have my three ring binder data sheets set up to record length to ogive for every bullet I load in that caliber. After 100 rounds I remeasure to see how much of the throat has been erroded and readjust my data.

[lal357]

never thought about writing down my measurements would let me know how quick the barrel is going might have to start.

[droach]

Slightly hijacking this thread but... Can anyone give me a "primer" on bullet seating depth and how changing depth could effect accuracy? How do I measure or determine where rifling starts? And can you fill me in on jumping and jamming? Thanks

[Nor Cal Mikie]

The right way to do that is to have the proper tools. Stoney Point / Hornady has the "proper" tools. With those tools, you can find where the rifling starts.
(And while you're at it, find the "actual" chamber length measurement so you'll know when and if you need to trim your brass)
Some guys will split a case neck so a bullet will slide in and out with very little resistance. That works also but I prefer the proper tools. ;) And every brand of bullet design is different so you have to measure all of them and keep notes.
After you get that measurement, you can set the OAL of your loaded rounds, (jam or jump to the lands) and adjust from there to see what will and won't work for "your" best accuracy.
And that measurement to the lands will change with the amount of rounds fired so keeping notes is important.
The only way to see how changing the OAL from a jump to a jam effects "your" accuracy is to see what "your" rig likes. Sometimes it makes a big difference and other times, nothing at all. That's the difference between shooting store bought ammo and rolling your own. You get to play and see what you can come up with. Find you most accurate load and work from there.
And make sure you "only" change one thing at a time. Powder, primer or bullet seating depth. Otherwise you'll end up chasing your tail trying to figure out "what" changes made the difference. ??? (been there, done that :-[) HTH, MIke.

[Rocca]

Slightly hijacking this thread but... Can anyone give me a "primer" on bullet seating depth and how changing depth could effect accuracy? How do I measure or determine where rifling starts? And can you fill me in on jumping and jamming? Thanks


You can find info all over the internet othat covers all these questions.
Finding the OAL for a given bullet :
http://www.youtube.com/watch?v=3lppK2jJ3XE
http://www.youtube.com/watch?v=Zlv1N0qIAwI
Many more videos also on the subject.

Heres a good article from Sinclair.
http://blog.sinclairintl.com/2009/03/26/determining-bullet-seating-depth/

Jumping/jamming-
Simply put Jamming is seating a bullet so far out that you are pushing the bullet into the riflings when you chamber the round.
Jumping is seating the bullet back so that once the bullet is fired it has to move forward a given amount before to makes contact with the riflings.

http://www.gunsamerica.com/blog/coal_cartridge_overall_length/

[GaCop]

The right way to do that is to have the proper tools. Stoney Point / Hornady has the "proper" tools. With those tools, you can find where the rifling starts.
(And while you're at it, find the "actual" chamber length measurement so you'll know when and if you need to trim your brass)
Some guys will split a case neck so a bullet will slide in and out with very little resistance. That works also but I prefer the proper tools. ;) And every brand of bullet design is different so you have to measure all of them and keep notes.
After you get that measurement, you can set the OAL of your loaded rounds, (jam or jump to the lands) and adjust from there to see what will and won't work for "your" best accuracy.
And that measurement to the lands will change with the amount of rounds fired so keeping notes is important.
The only way to see how changing the OAL from a jump to a jam effects "your" accuracy is to see what "your" rig likes. Sometimes it makes a big difference and other times, nothing at all. That's the difference between shooting store bought ammo and rolling your own. You get to play and see what you can come up with. Find you most accurate load and work from there.
And make sure you "only" change one thing at a time. Powder, primer or bullet seating depth. Otherwise you'll end up chasing your tail trying to figure out "what" changes made the difference. ??? (been there, done that :-[) HTH, MIke.


Well stated!

[droach]

Good info. Thank you.