Originally Posted by
W.R.Buchanan
Have a look at Lyman 311299. That is a pretty good bore rider design.
The intention of the bore rider design is that the smaller portion of the boolit indexes the boolit into the bore concentric with the centerline of the bore and the rear part or driving bands engage the rifling to impart spin.
I don't think the percentage of front versus rear portions of the bullet/boolit actually have very much to do with it. The front portion must be long enough to go into the bore at least 1-2 diameters, and the rear portion must be long enough so that it doesn't strip on firing and transfers the twist of the rifling directly to the boolit.
For this reason I want my boolits as close to actual bore size as possible but on the low side. MY NOE 311299 drops at .2997 which is about as close as you can get in the hole without engraving the boolit some amount.
That way the boolit is pre-aligned with the bore before firing unlike other styles of bullets/boolits that must align themselves at firing and literally jump into the bore from a distance and may or may not actually go into the bore perfectly strait.
Randy