Target Shooter 1

Left to right - Berger 155.5, Lapua 155 Scenar, HBC BJD, New Sierra, Berger VLD, PMP,
Bullet i 7
Berger 155.5 Fullbore
Lapua 155 Scenar
155 HBC BJD
(Australia)
Sierra 155 Palma (2156)
Berger 155 VLD
155 PMP (South Africa)
Sierra 155 Palma (2155)
Hornady 155 A-Max
Old Sierra, Hornady A-Max
Average
G7 BC
Retained
Velocity
(1,000yd)
fps
Wind
Deflection
(600yd)
Inches /
MOA
Wind
Deflection
(1,000yd)
Inches / MOA
0.988 0.237 1,302 27.3 / 4.4 91.0 / 8.67
0.988 0.236 1,298 27.4 / 4.4 91.6 / 8.73
0.989 0.236 1,297 27.4 / 4.4 91.6 / 8.73
1.018 0.229 1,257 28.5 / 4.5 95.9 / 9.14
1.039 0.225 1,228 29.2 / 4.6 98.5 / 9.42
1.041 0.224 1,227 29.3 / 4.6 99.2 / 9.45
1.092 0.214 1,161 31.1 / 4.9 106.7 / 10.17
1.100 0.212 1,152 31.4 / 5.0 108.3 / 10.32
Figure 3. Ballistic performance comparison for 8 Fullbore bullets starting out at 3,000
fps MV under standard sea level atmospheric conditions (59°F, 29.53 inches mercury
pressure).
Figure 3
the ‘old’ Sierra Palma MK
(#2155) and the Hornady
A-Max move another 15 to
17 inches sideways in the
wind and struggle to remain
supersonic, close enough
to 1,120 fps to see the
latter have some bullets in
a string risk dropping below
this velocity at the bottom
end of a typical MV spread
allied to slightly more
onerous atmospheric
conditions, such as lower
temperature and/or higher
pressure. Note that
performance variations in
the hypothetical 10mph
crosswind are much
reduced at 600yd, the
difference between the
‘best’ and ‘worst’
equating to just over a
half-MOA compared to
three times that amount
at 1,000yd, so having the
optimal bullet in ballistics
terms confers much less
advantage to the shorterrange
shooter.
So now that we have
these results, how do we
know what to make of
them? The sterile wind
deflection in a constant
10 mph crosswind
performance metric is kind
of useful, but what does
it mean in terms of points
in a match? Is there a
real, practical difference
between say 91” and 95.9”
of wind deflection (the 1st
and 4th bullets respectively
in the list), or is that just lost
in the noise? To attempt to
shed light on this question,
I’ll turn to modelling. The
results of a model are only
as accurate as their inputs.
The bullet performance can
be modelled accurately, but
Target Shooter 61