HB-9 updated text (PDF) - Corbin Bullet Swaging

(A note about those Herter’s bullets: these were most likely reject
bullets made because of a severe mismatch in a set of commercial swage
dies, but Herter’s was innovative enough to turn someone else’s rejects
into their “Model Perfect” offering of the season. Strange advantages were
touted for this bullet: it was said that the air went in a sort of circle around
that hourglass shape and somehow whipped around behind the bullet,
whacked it in the rear and drove it faster! If this were true, Herter’s discovered
a perpetual motion machine with a new twist. Imagine what
would happen if you accidently gave one of those bullets a thump with
your finger while it rested on the table: the air would start accelerating it
faster and faster until it was zipping around the room at supersonic speed,
blowing holes in all observed physics!)
The pressure ring is not a design feature: it is a physical fact of life that
gets in the way of having a nice parallel shank on the bullet and can
expand the case neck as the bullet base passes through, leaving the bullet
slightly loose. In a short-necked round like the .300 Savage, the pressure
ring is a real problem, since the case holds part of the ring and part of the
shank, and the bullet flops around as a result.
Most of the time, the pressure ring doesn’t hurt anything but if there
were a way to get rid of it without hurting accuracy in some other way, it
should be done. The best way to minimize it is to match the core seater
and point former dies very closely, more closely than you can do with a
regular micrometer. You can also make the bullets slightly oversized and
tapered, so the dies really eject easily, and then push the bullet through a
ring die that irons the sides perfectly straight: now you’ve got a factory
bullet! That’s the way it’s done. But that also tends toward a loose fit
between jacket and core: the core pushes in and stays there, while the
jacket springs back a tiny bit and loosens its grip on the core.
If you bond the core (using Corbin Core Bond flux and melting the
lead core into the jacket for a permanent adhesion), you can draw down
the shank of the bullet without any springback effect. But all this is not
necessary for target shooting and barely necessary for anything else so
long as the ring is only slightly 0.001 inch or less) larger than the rest of
the shank. If you have any problem with the bullet in a short necked case,
then this is worth some consideration.
The main thing is, don’t be suckered into thinking that you must have
this mysterious feature in order to have a top-quality benchrest bullet. It’s
just how they come out, no design required or intended, and rather than
admit it, many bullet makers in the past have turned it into a “feature”.
This is rather like the software bug that the technical support person claims
is actually a feature: it’s supposed to work that way, didn’t you know?
(Good thing software companies don’t design cars. Cars might have be-
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