Hunting Rifle Accuracy:
By Chuck Hawks
I believe it was Townsend Whelen who wrote that, "Only accurate rifles are interesting." As a general proposition I would tend to agree with him. Few things are more frustrating than a firearm that cannot be made to consistently hit the target.
Accuracy is important in a hunting rifle, but not all important. Especially on the Internet, accuracy has taken on an almost mythical status. No one seems willing to admit to shooting groups larger than 1 minute of angle (MOA). I have read absurd discussions on shooting forums about how to shave 1/10th MOA from a hunting rifle's performance and postings from (obviously inexperienced) shooters distressed because their new rifle could not produce sub-1" groups at 100 yards. It is as if these shooters are living in some sort of alternative reality.
Professional gun writers contribute to this mythology by routinely reporting rifle "tests" in which every advertiser's smokepole routinely shoots 1" groups (or smaller) at 100 yards. Ditto for every factory load, regardless of caliber or purpose. Sure they do!
I have written it before and I will write it again: these groups are achieved on a word processor, not in the field. At best what the writer means is that once, when the stars were momentarily aligned in the sky, he shot a 1" group with the test rifle. He will never admit in print that he shot nine other groups ranging in size from 2" to 4" with the same rifle.
However, the inexperienced and the gullible take these "test reports" to heart. The most absurd exaggeration is accepted without question, and endlessly repeated (and embellished) online. The boldest liars become authorities on marksmanship and rifle performance. It would be depressing if it were not so absurd!
Accuracy is relative. Realistically, there is no such thing as absolute accuracy, by which I mean a rifle capable of 0.0 MOA accuracy. Some specialized rifles can come very close, shooting what may look like one-hole groups, but there is always some variation, caused by the fact that no rifle or bullet is truly perfect. There is always some manufacturing tolerance, a tiny "plus or minus" factor in anything made by man that falls short of absolute perfection.
Accuracy can be defined in terms of group size at a given range, such as a 1" three shot group at 100 yards or 100 meters, measured from center to center of the points of impact. It can also be defined in terms of the angular dispersion of the bullets. Angle is described in terms of degrees, minutes of arc and seconds of arc. There are 360 degrees in a full circle, 60 minutes of arc in one degree and 60 seconds of arc in one arc-minute. For general purposes, one minute of angle equals a 1" group (center to center) at 100 yards.
What is meant by the term "practical" as applied to accuracy? The dictionary defines practical as: "Capable of being used or put into effect; useful." So the next question must be: accuracy useful for hunting what kind of game, at what range?
For the purposes of this little piece the answer to that question are the common species of antelope, goat, sheep and deer hunted in North America (and similar size game worldwide). These are often called medium size big game animals, or sometimes just medium game, and they range in size from the smallish pronghorn antelope and sub-species of whitetail deer weighing about 90 pounds on the hoof to sheep, mountain goats and mule deer than might average up to 200 pounds. Even very large members of these species seldom exceed 300 pounds in live weight.
The smallest of these animals offers about an 8" diameter heart-lung kill area and most offer at least a 10" kill area. So, to be conservative, let's say that our rifle needs to be able to put its bullets (from a cold barrel) into about a 6" circle at whatever range our skill and the trajectory of the cartridge we are using allows. This leaves a little room for error on even the smallest medium game animals.
For the hunter using a 100-150 yard hunting rifle, such as rifles chambered for what are fundamentally pistol cartridges (.357 Magnum, .44-40, .44 Magnum, etc.) or low pressure cartridges like the .38-55 and .45-70, a 4 MOA group will suffice. 4" groups at 100 yards don't look very impressive at the range, but 4 MOA groups mean all bullets within a 6" circle at 150 yards, about the maximum useful range of this class of cartridges. A .44 Magnum rifle that will put all of its bullets into a 4" circle at 100 yards is a deadly deer rifle, as accurate as it needs to be.
A 200 yard hunting rifle, such as a .30-30, .35 Remington, or .444 Marlin needs to print 3 MOA (3") groups at 100 yards. This means that all of the bullets will be landing inside of a 6" circle at 200 yards. A North American hunter can take any deer, sheep, pronghorn, or goat with such a rifle. In Townsend Whelen's day, few hunting rifles would shoot better than that. Many will today, but practically speaking it doesn't matter. 3 MOA is good enough for 100% kills out to at least 200 yards. A 200 yard rifle that shoots 1 MOA groups is not one whit deadlier than one that shoots 3 MOA groups.
The hunter with a long range rifle capable of taking medium game at 300 yards (such as a 6mm Remington, .25-06, .270 Winchester, 7mm Remington Magnum or .300 Winchester Magnum), needs a rifle that averages 2 MOA groups. Those 2" groups at 100 yards will open to 6" at 300 yards. Very few hunters can take advantage of more accuracy than that in the field, so 2 MOA represents the practical limit of accuracy for most hunters. I am sure that Col. Whelen would have classified such a rifle as very "interesting." Of course, it is nice if Old Betsy will shoot even smaller groups at the rifle range, but it is simply not necessary from a practical standpoint.
For the master shot with a trajectory table developed for his specific rifle and load, a high quality rangefinder, a solid rest, and shooting an ultra-long range cartridge like the .240 to .300 Weatherby Magnums, .264 Winchester Magnum, or 7mm Remington Ultra Mag, a 400 yard shot might be justified. If so, that hunter needs a rifle that will reliably shoot into 1.5 MOA. 1.5 MOA means a rifle that groups within 3" at 200 yards and 6" at 400 yards. This is a very interesting rifle indeed, particularly considering the muzzle blast and recoil of most ultra-long range cartridges. Such rifles are quite scarce in the real world. At 400 yards the merest twitch by the hunter, or a puff of wind 200 yards away, will throw the bullet clear out of the kill area. The inherent accuracy of the rifle has become a secondary consideration compared to other variables.
Groups better than 1.5 MOA are swell to brag about online, but irrelevant in the field. Accuracy beyond the practical limit is simply unnecessary. No one is justified in taking shots longer than 400 yards with any hunting rifle or cartridge. Sub-MOA rifles are nice, but irrelevant to the hunter.
Many other factors are more important to a successful and humane hunt, the functional reliability of the rifle and load being among them. This mitigates against hunting cartridges derived from PPC-type bench rest cartridges, for technical reasons that I don't have time to go into here. Examples of inappropriate hunting rounds include the WSSM, WSM and Rem. SAUM cartridges. Examples of cartridges designed to feed reliably from bolt action rifles include the .270 Winchester, .30-06 and .375 H&H Magnum. Compare, say, a .300 WSM to a .30-06 and note the differences in design, then buy hunting rifles chambered for cartridges that look like the latter.
Perhaps paramount among the factors more important than accuracy beyond the practical limit is the terminal performance of the bullet. It must penetrate into the vitals of the game to do its job and it must have expanded to destroy the maximum amount of tissue once it gets there. An adequately accurate bullet that does a good job of killing game is far preferable to a brilliantly accurate bullet that does a marginal job when it hits the target. Thus, while I always test a number of bullets and loads in each of my hunting rifles to find the one that gives the best accuracy, I test only bullets that are widely regarded as appropriate for the velocity and type of hunting for which they will be used. No match or other exotic bullets need apply.
My .257 Weatherby Magnum rifle, for example, will shoot at or just under 1.5 MOA (1.5" at 100 yards) with Weatherby factory loads using the 120 grain Nosler Partition bullet. The same rifle will shoot into 1 MOA or a little less at the same distance with Weatherby factory loads using the 100 grain Spire Point bullet. On light game the 100 grain Spire Point is a deadly bullet, but for general purpose hunting I load up with the Nosler Partition cartridges. The advantage of the heavier, super-deadly Partition bullet far outweighs a paltry .5 MOA difference in accuracy.
Copyright 2003, 2008 by Chuck Hawks. All rights reserved.