Orbiting Cherries and Scalable Boolit Design Real World Results?

[KVO]

A few of the semi-custom mold makers offer boolit designs for multiple calibers based on the same cherry orbited out for larger diameter. Most often these seem to be wadcutters though it's becoming common within rifle calibers within the limitation of gas check shank fit as well. For example, NOE makes a clone of the Lyman 358-432 with .41, .44 and .45 caliber versions. Per the print all are 0.639" long with identical band lengths, etc. I have the .38 and .44 versions that in my limited testing that produce reasonable accuracy on paper, though I can't say I'm amazed with the .44 version (not bad but not great either so far).

Does anyone else have real world experience with these spin off designs? There is a shift in center of gravity, SD, and many other subtle changes occurring. Is something inherent to accuracy or performance from the parent design lost in translation between calibers?

[country gent]

With the CNC machines most are running today. The circle pocket ( machine drops to depth and cuts a flat circle) the undersize cutters can cut several calibers. Done right they may have a body mill with the grease grooves and a nose cutter separate so almost any nose and body can be put together. The big advantage to this is the blocks are tight together so no chips or swarf get between them. No expensive centering vises are needed. cutter grind is simpler with this you only need to know the cutters dia. with the cherry it had to be ground to the correct size and form.

There are plunger EDMs that can do this with a carbon electrode turned on a small high speed lathe. A lot less cost in the cutters. And cheaper machinery than a cutter grinder and such. Set up right as to machine lay out the operator could turn the next pilot while the EDM is burning a mould. The forge dies for snap on and mack wrenches are produced with EDMs. I did several moulds on the charmay sinker at work.

[samari46]

If this is about scaling up a bullet mold from one caliber to the next,then I had a buddy who was heavily into BPCR. Had the Lyman 457125 500 grain mold duplicated in 50 caliber for his 50-90. And yes it did shoot very well. Frank

[KVO]

Samari46, yes sir, referring to scaling up an identical design to a larger caliber specifically with the same length.

Example:

http://noebulletmolds.com/NV/images/n.o.e._bullet_moulds_360-162-wc_pb_aw3_sketch.jpg

http://noebulletmolds.com/NV/images/n.o.e._bullet_moulds_432-237-wc_pb_bl4_sketch.jpg

http://noebulletmolds.com/NV/images/n.o.e._bullet_moulds_413-215-wc_pb_bl3_sketch.jpg

http://noebulletmolds.com/NV/images/n.o.e._bullet_moulds_454-264-wc_pb_bl5_sketch.jpg

[samari46]

KVO, yeah that really makes the difference with a proven bullet and scale it up and shoot it out of a rifle in a different caliber Thanks for the drawings. Frank

[Hamish]

The two that I am most familiar with are the 311-165 Ed Harris SKS design and the 311-008 orbited out to .325 by JTKnives and NOE respectively. They work.