Wildcat bullets offers an 8, 10 and ULD ogive. Can someone tell me if these are standard designations like a thread pitch or a guage and where they come from and what .30 cal bullet has each of these ogives so I can look at an example of each of them on line?
Ogive question.
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Jon A
Well-Known Member
It basically describes the radius of curvature of the "nose" part of the bullet relative to the caliber. The higher the number, the larger the radius--the "flatter" the sides of the nose will be and (all else being equal) the longer the nose will be. It gets more complicated than that when you talk about secant ogives and offsets, but that should give you a basic idea. Here's a visual:
Many Sierra MK's, Nosler BT/AB's are around a 6 caliber tangent ogive. A pretty good compromise between aerodynamics (high BC) and not being picky about the rifles throat, seating depth, etc to provide good accuracy.
Many Hornadies (A-Max, Interbond, SST, "Spire Point"), Swift Sciroccos, old XBT's, etc use a more aggressive (~8-10 Caliber) Secant ogive. This is better aerodynamically (higher BC) but can be pickier about which rifle they shoot the best in, seating depth, etc.
VLD, ULD, get even more aggressive in search of higher and higher BC's.
That's very generalized, but hopefully it gives you a decent idea what the terms mean.
Many Sierra MK's, Nosler BT/AB's are around a 6 caliber tangent ogive. A pretty good compromise between aerodynamics (high BC) and not being picky about the rifles throat, seating depth, etc to provide good accuracy.
Many Hornadies (A-Max, Interbond, SST, "Spire Point"), Swift Sciroccos, old XBT's, etc use a more aggressive (~8-10 Caliber) Secant ogive. This is better aerodynamically (higher BC) but can be pickier about which rifle they shoot the best in, seating depth, etc.
VLD, ULD, get even more aggressive in search of higher and higher BC's.
That's very generalized, but hopefully it gives you a decent idea what the terms mean.
Mikecr
Well-Known Member
Were the Wildcats secant or tangent?
bailey1474
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Thanks. I had the same question, just hadn't asked it yet.
Fiftydriver
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Mikecr,
I believe both designs are used depending on bullet.
Alot of the ULD bullets have an ogive between 10 and 15.
Good Shooting!!
Kirby Allen(50)
I believe both designs are used depending on bullet.
Alot of the ULD bullets have an ogive between 10 and 15.
Good Shooting!!
Kirby Allen(50)
[ QUOTE ]
Were the Wildcats secant or tangent?
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I don't know. when I spoke with Richard on the phone he just used the numbers 8 10 and ULD.
That would be a good next question for him, which one he uses.
Next question for you guys- What is the difference between a secant and tangent ogive technically speaking?
What effect do we see with one over the other practically speaking?
Were the Wildcats secant or tangent?
[/ QUOTE ]
I don't know. when I spoke with Richard on the phone he just used the numbers 8 10 and ULD.
That would be a good next question for him, which one he uses.
Next question for you guys- What is the difference between a secant and tangent ogive technically speaking?
What effect do we see with one over the other practically speaking?
From what I am putting together the ogive based on caliber would look something like this.
We start with a 30 cal diameter. I then made 3 circles that were 6 8 and 10 times as big. If we use the section cut on a plane horizontal to the center of the caliber we end up with half of a bullet tip profile. I'm assuming this is a tangent ogive???
If this is right then how come in the graphic above we see .5 for the ogive that is semicircle instead of 1. Are we dealing with the caliber radius or the diameter?
We start with a 30 cal diameter. I then made 3 circles that were 6 8 and 10 times as big. If we use the section cut on a plane horizontal to the center of the caliber we end up with half of a bullet tip profile. I'm assuming this is a tangent ogive???
If this is right then how come in the graphic above we see .5 for the ogive that is semicircle instead of 1. Are we dealing with the caliber radius or the diameter?
Richard338
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The number of calibers dictates the RADIUS of the circle describing the ogive. Thus a 10 caliber ogive for a .338 bullet would be described using a circle of RADIUS 3.380".
Mysticplayer
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- Jul 27, 2001
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So does this mean that any calibre can be made to the same ogive thus BC? If this is true, then if we can figure out how to make them, you could have a 22cal bullet with a BC of 0.8 or whatever. That would have a ogive of 15 cals or so. Wouldn't be much more then 120gr so pretty easy to launch.
No recoil with ballistics on par with the super big 338's. Very interesting...
Jerry
No recoil with ballistics on par with the super big 338's. Very interesting...
Jerry
Alucard
Well-Known Member
You would need one hell of a case to launch a 120gr .22 cal to get the velocity to reach the 0.8 BC. I think that there is a limit to BCs in every caliber in useable bullet weight range. But, truely, I don't know much about BCs and what not.
[ QUOTE ]
The number of calibers dictates the RADIUS of the circle describing the ogive. Thus a 10 caliber ogive for a .338 bullet would be described using a circle of RADIUS 3.380".
[/ QUOTE ]
So the numbers in my illustration should have been 3 4 and 5?
The number of calibers dictates the RADIUS of the circle describing the ogive. Thus a 10 caliber ogive for a .338 bullet would be described using a circle of RADIUS 3.380".
[/ QUOTE ]
So the numbers in my illustration should have been 3 4 and 5?
[ QUOTE ]
So does this mean that any calibre can be made to the same ogive thus BC? If this is true, then if we can figure out how to make them, you could have a 22cal bullet with a BC of 0.8 or whatever
[/ QUOTE ]
Among many other things BC is also a function of weight. I cant imagine a 42 gr .22 bullet approaching the BC of a normally shaped 168 grain .30 cal no matter how long the ogive is.
So does this mean that any calibre can be made to the same ogive thus BC? If this is true, then if we can figure out how to make them, you could have a 22cal bullet with a BC of 0.8 or whatever
[/ QUOTE ]
Among many other things BC is also a function of weight. I cant imagine a 42 gr .22 bullet approaching the BC of a normally shaped 168 grain .30 cal no matter how long the ogive is.
Jon A
Well-Known Member
[ QUOTE ]
So does this mean that any calibre can be made to the same ogive thus BC? If this is true, then if we can figure out how to make them, you could have a 22cal bullet with a BC of 0.8 or whatever.
[/ QUOTE ]
Remember, of equal importance as the aerodynamic shape to the BC, is the bullet's sectional density.
So does this mean that any calibre can be made to the same ogive thus BC? If this is true, then if we can figure out how to make them, you could have a 22cal bullet with a BC of 0.8 or whatever.
[/ QUOTE ]
Remember, of equal importance as the aerodynamic shape to the BC, is the bullet's sectional density.
