April 2026 (2) - Flipbook - Page 37
While I have just begun to
scratch the surface of fully understanding these concepts. Which
I freely admit. But some terms
and their meaning there of, have
began to make some sense. While
I am far from understanding all
the applied math, I do understand or at least have a rudimentary understanding of the modeling employed. And the results are
compelling.
CD. Drag Coe昀케cient. This is Only
determined with, 昀椀red data down
range, captured. Only long range
Doppler data can give one this
data.
God bless Black Powder!
The G1 bullet pro昀椀le is what closest 昀椀ts our bullets drag and ballistic coe昀케cients. Thus it is better
for modeling of our bullet’s down
range performance. This can be
imputed into the JCM calculations as either a G1 or G7 drag
pro昀椀le. We should use the G1
modeling entirely, as it’s closest
suited to our type of projectiles,
both the paper patch and grease
groove bullets.
To better deal with the transition
from transonic to subsonic bullet
speeds, the 昀氀at base bullet is
required or desired for best per-
formance. Faster twist Barrels
are generally required also, this
is necessary to help maintain
stability when passing through
the PIP. Remember our bullets
spend most of their life cycle in
the transonic speed range. The
maintaining of our bullet’s nose
shape is also important, harder
alloys
such as 16-1 or my choice of
14.5-1 help maintain our nose
pro昀椀le.
Litz gives an excellent example
of the old 168 BT Sierra Match
King failure in the 308 past 800
yards, curing the problem with
the M118LR 175 gr bullet going
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