Ogive Pictures, please.

[Terry]

I'm looking for pictures of ogives for the 103-108 class of 6mm bullets.

Pictures that demonstrate the difference would be best.

Trying to get a grip on 13 ogive, 15 ogive, VLD types.

Thanks!

 

[rammac]

You could simply create a series of curves equal to 13 and 15 times the caliber diameter and compare them but I'm not sure that this would help you visualize the differences since it would be very small.

I found an article by Daniel Lilja wherein he describes how to compare ogives to throat angles. He has a chart at the end that includes the throat angle for a 15 caliber Secant 6mm (2.77 degrees). He includes a copy of a basic program that he created to calculate mathematically the relationship between the ogive slope angle and the throat angle.

http://riflebarrels.com/a-look-at-bullet-ogives-and-chamber-throat-angles/

 

[Chuckhunter]

Left to Right 6Bra with 103Gr (13 ogive)bullet, 6MM Dasher with 105Gr. (15 ogive bullet), 6.5X47 Lapua with 130Gr. Berger hunting VLD. Hope it helps.

 

[Terry]

Left to Right 6Bra with 103Gr (13 ogive)bullet, 6MM Dasher with 105Gr. (15 ogive bullet), 6.5X47 Lapua with 130Gr. Berger hunting VLD. Hope it helps.

It does.

Thanks!

I see 13 is straighter, 15 more rounded.

Thanks!

 

[BoydAllen]

Are you up to speed on the differences between tangent, secant, and hybrid ogives? There is more to this than the numbers.

 

[Terry]

Are you up to speed on the differences between tangent, secant, and hybrid ogives? There is more to this than the numbers.

Yes.

Thanks

 

[Chuckhunter]

Correct Terry, the 15 ogive shot decent from my Dasher but not well out of the Bra. The 13 ogive shot much better from the bra. Not saying that was the only variable as the 103 was less weight and also less bearing area which could have been responsible for better performance, or a combination of all three factors.

 

[hrlincoln]

It does.

Thanks!

I see 13 is straighter, 15 more rounded.

Thanks!

If you were comparing apples to apples, the 15 would appear to be more pointed/sleeker and the 13 more rounded. The two bullets in question have different ogives...the 13 appears to be a secant/possibly a hybrid, whereas the 15 looks to be tangent. The numbers aren't really revealing unless you're comparing tangent to tangent, or secant to secant. And then there's the hybrids

In case you haven't seen this:

www.accurateshooter.com/ballistics/tangent-vs-secant-vs-hybrid-ogive-bullets/

 

[Terry]

In just a few post we have shown how confusing this can be.
Perhaps this is a good topic for a right up with pictures.

 

[Dusty Stevens]

In just a few post we have shown how confusing this can be.
Perhaps this is a good topic for a right up with pictures.

Or just figure out which bullet shoots in your rifle. The higher the number the more pointy it is.

 

[Dans40X]

Terry,
As previously posted-
www.accurateshooter.com/ballistics/tangent-vs-secant-vs-hybrid-ogive-bullets/

led to water....now drink

 

[Intheshop]

"Confusing" is trying to describe to someone the how/why seating depth changes effect the tune with different ogives. Because rate of twist and leade angles change this relationship..... further "complicated" by individual technique during bullet seating.

Try some different shapes..... pay real attention to your seating stem and how easy it is for you to get your depth numbers. Good luck with your project.

 

[Terry]

Terry,
As previously posted-
www.accurateshooter.com/ballistics/tangent-vs-secant-vs-hybrid-ogive-bullets/

led to water....now drink

Not nice!

I have read this. This is not what what I'm looking for. After numerous searches for pictures of the various ogives, I decided to ask. An understanding of the various numbers is my quest.

Thanks

 

[Dusty Stevens]

Hey terry if you have a machine shop local to you they will have an optical comparator and will project those bullet shapes onto a big screen for you. Then you can see the differences when theyre on the wall a few feet high instead of actual size.

 

[Terry]

Hey terry if you have a machine shop local to you they will have an optical comparator and will project those bullet shapes onto a big screen for you. Then you can see the differences when theyre on the wall a few feet high instead of actual size.

Great idea!

Thanks

 

[BoydAllen]

Terry, do you know what the numbers refer to?

 

[BoydAllen]

Perhaps this will be of some assistance.

 

[Terry]

Far better than what I found on the internet!

Thanks!

 

[Terry]

This is the kind of thing that makes this stie a Gold Mine.

Thanks so much for all your help!

 

[BoydAllen]

Another way to get a better grasp of ogive design is to take a ruler and compass and draw the various ogives following the method shown in the illustrations of how to do that on the internet. You can to this for tangent as well as secant I think that after you do that, you will have the whole thing firmly under control.
https://mathscinotes.files.wordpress.com/2011/01/spitzer2.png?resize=444,354
http://www.appliedballisticsllc.com/Articles/ABDOC2.1 - OGIVECOMPARISON.pdf