Even with very accurate rifl es, prairie dogs are pretty
tough to hit consistently at more than 400 yards, and under normal fi eld conditions hitting more than we miss at 300-350 yards is pretty good shooting. With no wind, of course, many of us turn into real long-range wizards. One afternoon I killed something like 10 prairie dogs with 12 shots at 550 to 575 yards, using a very accurate heavy-barreled 223 Remington and a Ramshot scope equipped with a grid reticle. But en- countering a totally windless day on the high plains is much like running into Brad Pitt and Angelina Jolie at the saloon in Two Dot, Montana, theoretically possible but not very likely. Also, prairie dog shooting means quickly repeated shots
at varying distances. Spinning elevation turrets like a target shooter can be done, but it’s normally quicker to use a multi- point “ballistic” reticle. Even then, a fl at-shooting round takes some of the error out of using each point for aiming, and at less than 400 yards high muzzle velocity fl attens trajectory more than a super-high ballistic coeffi cient. Rodent shooters use highly frangible bullets, so that
just about any hit results in a clean kill. High velocity helps expansion, and even though heavier bullets retain more veloc- ity, out to 400 yards a 40-grain bullet from a 223 will still be traveling faster than a 55, everything being equal. Top muzzle velocities vary depending on the source of
loading data, but in general it’s possible to start 40s at around 3,800 fps and 55s at 3,300 from a 24" barrel. To level the playing fi eld, let’s make both bullets Nosler
Ballistic Tips and run them through Sierra’s Infi nity program. In typical prairie dog conditions (3,000 feet above sea level at 80 degrees) at 400 yards the 40-grain bullet is still traveling at 2,234 fps and the 55-grain at 2,094. This is part of why the 40-grain shoots noticeably fl atter to 400 yards. But hey, we all know that heavier bullets drift less in
the wind. Let’s look at the Sierra Infi nity wind-drift numbers for a 10 mph, 90-degree crosswind: The 40-grain drifts 17.2 inches and the 55-grain 16.5 inches. The difference is less than the width of a standing prairie dog. Some of the highly explosive effect of lighter, faster
bullets is also due to bullet rotation. A 40-grain bullet from a conventional 1:12" twist 223 leaves the muzzle spinning at 228,000 revolutions per second, while a 55-grain bullet starts at 198,000 rpms. Unlike muzzle velocity, rotation doesn’t slow down much at longer ranges, so a 40-grain bullet is not only going 140 fps faster than a 55-grain, but spinning 15% faster. No wonder 40-grain bullets normally provide more “lift” out there on the prairie. Even if we increase the bullet to about 70 grains and use
a 1:9 twist, the 40-grain still holds its own. The 70-grain Berger VLD has the highest listed ballistic coeffi cient among 70-grain .224 bullets, but when started at 3,000 fps (tops for a 70 from a 24" barrel) it’s still going only 2,176 fps at 400, slightly slower than a 40-grain Ballistic Tip, so doesn’t shoot as fl at. At 12.3 inches wind drift is substantially less with the
70-grain VLD, and rotational velocity is also higher because of the faster twist, 240,000 rpm. But the VLD, like any other high-BC hollow-point, simply isn’t going to expand like a plastic tip. It would be among the top choices to hit a prairie dog at, say, 700 yards, but it doesn’t compare to a 40-grain plastic tip at 400 yards – especially when a 40-grain bullet in a 1:9 twist starts out at more than 300,000 rpm.
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