7 or 10 tangent ogives

[fullersson]

I read an article on accurateshooter.com about the 30br. That article was talking about shooting bullets with either 7 or 10 tangent ogives. I know what tangent and secant ogives are, but I don't know what is meant by 7 or 10. Would someone please explain to me what is meant by 7 or 10 tangent ogives. Thanks.

 

[AJ172SBCT]

Here you go,
Click Here

Jacques

 

[fullersson]

Thanks for the help.