1 ogive radius

[candt]

I am shopping for a bullet mold, and I have been considering the 230 gr Lee tumble lube bullet. On their website it says it has a 2 ogive radius. Lee also makes a conventional style bullet with a 1 ogive radius that is 228 gr. I have no idea what this means. By looking at the pictures of the bullets, it appears that the 2 ogive radius bullet is taller, while the 1 ogive radius bullet is shorter and more blunt. What does this number of ogive radius refer to?

 

[WayneConrad]

Wikipedia: Ogive.

I'm glad you asked this. I've been wondering what all this ogive stuff was about, and I had to go do some research to have a chance of answering (disclaimer: I could have it all wrong; I'm a newbie at this).

If the bullet is a "secant ogive", then the curve of the bullet nose is circular. The bullet ogive is how far from the edge of the bullet is the radius of the circle.

The ogive radius is expressed in bullet widths. An ogive radius of 0.5 is half the width of the bullet, which would make a secant ogive bullet nose be perfectly round ("ball" ammo, I think). The larger the ogive radius, the pointier the bullet. I think that if you increase the ogive radius, the nose now holds more lead and is longer; if you want to keep the same weight you have to shorten the base but you'll still end up with a longer bullet.