By now, nearly
every serious shooter has either used or seen ballistic software that models, or
predicts, the flight of a bullet. This kind of ballistic study is called
exterior ballistics, but did you know that there are two other ballistic
disciplines: interior and terminal ballistics? Terminal ballistics is the study
of bullet effects on targets (game or varmints), while internal ballistics is
the study of what occurs while the bullet is still in the barrel of the firearm.
While I know of no widely distributed terminal ballistics software, I recently
received a copy of a unique internal ballistics application. This
fascinating piece of software models everything that goes on inside a firearm,
to include muzzle velocities, pressure curves, bullet exit pressures, and a
litany of other ballistic tidbits that you never dreamed of seeing. Called
QuickLOAD, it is very different from other software that simply “e-copies”
reloading manual data, for it calculates mathematically what a given charge of
powder will do to a specified bullet.
While I
generally love high muzzle velocities, I am not so enamoured with them that I
try to get the last few feet per second from a load at the expense of accuracy.
I suspect many readers share my level of enthusiasm. Furthermore, if I can get
a light-barreled .223 to shoot in the 4’s or 5’s, I move on to other loading
projects or just plain head to the field. And while I love to read loading
manuals, I must confess that I do not own either a lot or the very latest. In
short, load development is a necessary evil, not a pleasure. All of those
personality defects make me a perfect candidate to use and write about QuickLOAD.
You see, unlike anything else I have seen it estimates the muzzle velocity and
pressure of any handload, shortening the time it should take to come up with a
load.
These days
there is a great deal of interest in ultra-long range rifles. The April 2000
issue of The VARMINT HUNTER Magazine contained an article by Matthew Miller that
discussed using veritable cannons for long-range whistle pig shooting. (By the
way, Matthew, ever hunt with Fritz Hein in Namibia? I think I remember seeing
your name in the guest book.) Such rifles are by no means prairie dog shooters,
but many hunters would rather take one long poke and score a hit than spend a
day shooting hundreds of rounds at lesser ranges. Besides, in the East, many
hunt in the evening after work. That, combined with the nature of woodchuck
hunting, makes laying down a daylong field of fire a difficult proposition.
I admit to
occasionally being smitten with the long-range bug myself. To help me shake
this bug, I am now working with three different long-range rifles, Remington
700s all. The first is a .220 Swift with a Shilen fast-twist barrel; this is
designed to shoot heavy bullets and dodge the huge ballistic problems that
plague lighter bullets. The second rifle is another Shilen barrel, this one a
cannon in 7mm STW. The third rifle is a stainless fluted Sendero in the even
larger .300 Remington Ultra Mag. Gordy Gritters is currently rebedding the .220
and lapping the lugs. I bedded the 7mm STW myself; preliminary groups of 3
shots (which will go to 5 shot groups) were all less than an inch with one load
in the 2’s. The .300 produced 3 shot groups of less than an inch out of the
box, but I suspect it will go to Gordy as well – the stock pops out of the
action like a jack-in-the-box when the action screws are loosened. How did I
arrive at starting loads for the two guns in possession? Well, it was all
pretty simple – I started with one line of powder – a line of powder that
previously proved to be remarkably consistent.
One
sought-after virtue in any long-range rifle load is consistency – consistent
accuracy and consistent muzzle velocity, to name a few. Consistent muzzle
velocity is not as simple as letting five shots rip across a chronograph and
then studying the summary statistics; you see, that wonderfully consistent load
might not be quite as predictable in the winter when you are lining up a coyote
in your sites. As you may know, many powders are severely affected by changes
in atmospheric temperature - generally, the colder the temperature, the slower
the muzzle velocity. Often the results are shocking – as much as 150 fps, which
is certainly enough to miss at moderate, let alone extended, ranges. To combat
this, my initial plans for these long range rifles called for using Hodgdon’s
Extreme line of powders, since earlier work showed these to be quite uniform and
consistent (8 fps velocity change from –20 to 105 deg F) under a wide range of
temperatures. For the two big boys, that meant either H4831 or H1000, and since
I had plenty of H4831, that is what I had in mind when I turned to QuickLOAD for
initial load identification. While the .220 was in Gordy’s hands and I waited
for the latest batch of Nosler BT pills to arrive, I took the shrink-wrap off of
QuickLOAD and popped the disk into my PC.
