Tapered bands on a bore rider.

[Iron River Red]

I have bought a couple of bore rider molds and chose a tapered front band when on the design software.

Should the bullet, once cast, have a smaller diameter on the front of the band?

I was thinking of having some taper to the front band to assist with alignment once the bullet enters the rifling. The band was selected to be long and no crimp groove to assure good sealing and bearing surface too.

After casting the bullets and then sizing them to .285", I noticed the front band is completely sized and I don't have the taper I was looking for. The design should have had .002" of taper and the bullet tolerances was ordered to be +- .001". I should s3ee some taper if the mold is cut correctly shouldn't I?

Maybe its just a waste of time...?

Just curious now. The bullet is a pain in the tail to run anyway.

135gr RNFPGC at .285" is the specs of the mold.

[JDL]

IRR,
What are the specs of your mold? Have you miced the boolit before and after sizing? I have 2 molds that are cut with the tapered front band and are only from bore to groove diameter and they are pretty hard to see. You must have a tight chamber throat by sizing to .285", if it is a 7mm.-JDL

[powderburnerr]

I only have a larger size bore rider but it has the front three bands at 446 ,447 ,448 and the 4th 5th and 6th band are 458 I either pan lube it if I want to fill all grooves or just lube the bottom three grooves........ Dean

o yes they are very distinctively tapered

[Buckshot]

............Well there are tapered boolits, tapered bands and stepped bands. If it was supposed to be a true tapered band, then yes the leading edge should be smaller in diameter. Depending upon the width of the band would determine the difficulty in grinding a tool to cut them.

Eagan used to offer tapered multi band boolit moulds, mainely to the schuetzen trade, but others too. They weren't cheap. Maven has a taper die
made by an outfit no longer in business.

Stepped bands, such as Powderburner is talking about are much more common, easier to produce and do much the same aligning work that a solid taperd band would do.

http://www.fototime.com/ADF9F422ACC2AA7/standard.jpg
On the left is a custom 8mm booit I had Lee produce with stepped bands. The nose is .318", the first band is .320" and then the remaining ones are .326". Just the leading edge of each band engraves the lands. The one on the right has been pushed up through a Lee .314" die for use in a cranky Argentine.

http://www.fototime.com/{5F928684-87C2-4545-A913-577BC7C20F8B}/picture.JPG
Another tapered slug. On the left is a Saeco 225gr slug for 38-55's. It's .373" on the front band and .381" on the base. Like the 8mm slug, the bands are stepped increase and not truly tapered.

How was the mould speced? Do you have a photo or the band diameters and lengths? It could be the mould was cut out of spec.

.............Buckshot