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From: (Bart Bobbitt)
Subject: Re: [RIFLE] soft-point vs. hollow-point bullets?
Organization: Hewlett-Packard Fort Collins Site

Brian Woodroffe ( wrote:

: Although all US match bullets that I know of are drawn from tail to point
: (ie imperfections at the nose), the highly accurate Lapua D46 bullet is
: drawn the other way; ie you can see the lead core when viewed from the
: base.

Those Lapua D46 rebated base bullets are accurate indeed.  But they have
not reached the success of Sierra match bullets here in the USA.  Several
machine rest tests over the years have shown Lapua match bullets to give
about the same-size groups at 600 yards as Sierras; with about a 5%
exception.  That exception is the 1 in 20 bullets that opens up the
otherwise very small group.  It's kind of like saying that out of a box of
100 D46 bullets, 95 of 'em will shoot Xes at 600 (or 1000) yards, and the
remaining 5 will be very wide 10s or more likely 9s.

In contrast to this well-known situation by the top highpower shooters,
the smallest 10-shot, 600-yard groups I've ever seen were fired with D46
185-grain bullets.  A Hart-barreled pre-64 Model 70 match rifle was put in
a machine rest and tested with D46 bullets at 600 yards.  Several 10-shot
groups were fired.  Ranging from just under 1 inch to just under 2 inches,
that unto itself is a credit to Finland's most favorite bullet.  Some of
these test groups were sent to Lapua by the person who produced them.  Lapua
was convinced that publishing one group as part of an advertisement would
no doubt be worthwhile.  The group shown in Lapua's advertisement in an
early 1970s American Rifleman Magazine pictured a knot of 10 shots of about
1.1 inches center-to-center; they were convinced that nobody would believe
the smallest, .85-inch 10-shot 600-yard test group.  After that ad appeared,
a lot of folks scurried to their nearest Lapua bullet dealer and bought them
by the thousands.  And they did so totally unaware that after several of
those very tiny groups were shot, subquent ones from the same 100-bullet
box of bullets occasionaly went way out of the main group cluster about
5 to 6 inches.  Oh well, such is life.

Extensive tests have proven that a bullet's tip can be somewhat imperfect
and they will still produce very tiny groups at all ranges.  But the base
junction with the bullet's body, or bearing surface, dimensional uniformity
typically is the most important part of the outside part of a bullet for
accuracy.  Sierra's first 30 caliber match bullets were full jacketed with
the lead core exposed at the base.  As these were far superior to the then
popular 173-gr. M2 military match bullet for accuracy, they soon began to
win the matches and set the records.  Interestingly enough, some lots of
Sierra's 180-gr. spitzer boattail hunting bullet shot as accurate as their
180 or 200 grain FMJ match bullets.  Sierra started investigating what is
really the best manufacturing method for accurate bullets.  Designs included
several boattail angles/shapes, ogives and points. After putting
several thousand bullets down range from barreled actions clamped in machine
rests, they found the answer.  Bullet jackets drawn from the base forward
and after jackets are pushed in, then run through a pointing machine to
form the final boattail and ogive/point had three extremely repeatable
dimensional situations:

  * Straight boattail bullets shot more accurate than rebated ones.

  * Runout at the boattail-body junction was much more unifor with hollow
    point bullets compared to solid point ones.

  * Test groups with hollow point bullets were typically 15 to 25 percent
    smaller than with full-jacketed ones.

Their first hollow point match bullet was their 168-gr. International
and was soon followed by the 190-gr. Match King.  The rest is history.


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