I�ve come across a box of these bullets.
It looks like an ordinary SP but it has 5 thin "lines" app one millimeter from the base.
The caliber is .224 and the weight is 55 grain.
Anyone who could help me out here?
//Rolf

I used to use these all the time. They have solid copper bases, with lead fotward of that.

The little rings are groove diameter (appx. .224") and the rest of the bullet is bore (land) diameter (appx .218") so that only the little rings reach the actual bottom of the grooves. Not only were the little bullets accurate, they were excellent performers. I once killed two whitetail does with one shot from a .22-250 using the 55 grain Zippedo. The solid base makes a non-expanding platform which increases penetration.

I assume that Nosler discontinued them in favor of a more conventional (but still solid-base) design because of manufacturing costs (?). Barnes has recently come out with a "ringed" bullet. There have been others through the years.

These haven't been made in many years. If you shoot them, you may want to keep some (and the original box) for collecting purposes.