The word “empirical” is often used when describing data, data that is produced from testing and observation. It is an important distinction from claims, theories and assertions. The basic notion is that empirical data is reproducible given the same test conditions. A claim, marketing brag, or assertion needs no such basis. Theories that are well-supported by data and have not failed any competent tests are dubbed scientific laws.

Over the years, scientific laws have been modified when more accurate data becomes available. Discussions of this nature may sound dry and boring compared to the less accurate or more bombastic claims. It sounds a lot more exciting when things smoke clays or kill ducks dead. That's just human nature. "Crushing clays" is supposed to be better than just smashing them and killing ducks dead is apparently supposed to be better than cleanly bagging them.

Although there is no other way to actually kill a duck other than dead, we respond to cartoon descriptions better than things that can be shown. Things that are proven and factual are often dismissed due to their boring accuracy. The sizzle is often more interesting than the bacon itself. The only sizzle present in this article is that the facts sometimes collide with what we have been told to believe for so long that we have accepted it without question.

I. NO GAUGE IS INVARIABLY BETTER THAN ANOTHER

The inaccurate notion of gauge, how many spherical lead balls of a certain diameter it takes to equal one pound, has always been only a suggestion of bore diameter. A larger bore diameter means a bigger hole in your barrel, but scant more than that. A slightly larger hole in the barrel, whether it is referred to as overbored, backbored, or something else does not affect pattern quality. Quite the opposite, from many sources including the recent Dr. A. C. Jones book, it has been shown to have no effect. What an excessively large bore diameter has been shown to do is affect reliability with fiber wads, leaving you with a barrel of unburnt powder.

When gauge comparisons are made, what can be shown is that yes, a higher density pattern can be usually thrown with a 12 gauge versus a 20 gauge. This is only interesting or valuable if you need a higher density pattern than you already have. The original Parker shotgun was a 14 gauge, a year later the 11 gauge Parker was introduced. The 14 gauge doesn't get much love these days, nor does the 24 gauge. Don Zutz wrote of his Neumann SxS 24 gauge grouse gun, a fad that never happened in the U.S. In the early 1960s, Winchester toyed with a relaunch of the 14 gauge, making a few in the Model 59 platform, but there was little interest. Had they convinced people that it "carried like a 16, but hit like a 12 gauge" perhaps the interest would have been higher?

The potency of gauge is primarily payload related. For example, one readily available but extremely good lead turkey shell is the buffered Federal PFC159F shell. It is a 3 inch unfolded length 12 gauge shell with a 2 ounce payload. No 20 or 16 gauge shell can complete with the payload in this shell, you can't put more pellets on your target than comes out of the muzzle, so naturally payload wins the day. A good 20 gauge 1 oz. load and a good 1 oz. 12 gauge load are far more closely matched, as you might imagine, hardly enough to change your day on the dove field. Payload well overshadows all other considerations. The best available version of the truth is that with similar payloads, a 28 gauge, 20 gauge, and 16 gauge are all closely matched with each other. A 12 gauge sometimes provides tighter patterns at the high-constriction end of the spectrum. Phrased differently, unless you hunt and shoot with the goal of “extra full” or “extra-extra full” pattern percentages in mind, it isn't enough to matter. If a 60% percent pattern percentage is what you seek at 40 yards, gauge does not matter.

II. PERFECTLY SPHERICAL PELLETS ARE BEST

Redundantly proved, the best profile for a pellet in a shotgun is perfectly spherical. The more you get away from sphericity, the more patterns tend to degrade at range. This is true for lead or for steel, with no exceptions than can be shown. It is also just as true for other shot materials. The problem with steel is its very poor density, so the far better density of Nice Shot and Kent Tungsten-Matrix neatly dwarfs the slight lack of sphericity.

III. PREMIUM INTERCHANGABLE CHOKE TUBES CAN PATTERN AS TIGHT AS PERMINENT CHOKES

It is well-proven that screw-chokes can throw patterns just as dense as solid choke tubes. A. C. Jones documented this yet again. Turkey hunters have known this for many years. Kim Rhode, Olympic gold medalist and eternal international medalist uses screw-chokes. There is no dispute, screw-chokes perform as good as fixed chokes. The tightest patterns that can be thrown from a commercial shotgun today are with screw-chokes. The reason is very simple: with screw-chokes, you can increase constriction with a specific gun and specific shell until increased constriction no longer has a beneficial effect. With fixed choke guns, it is difficult to sand metal back on.

IV. FACTORY CHOKE TUBES ARE OFTEN POOR

Yet again, Dr. A. C. Jones expressed dismay and puzzlement over the sad state of factory screw-chokes. In his testing, Dr. Jones didn't exactly “cheat,” as he did explain precisely what was used. He used Nigel Teague custom chokes. Three Teague Precison long extended choke tubes runs 264 pounds for a single barrel shotgun, 327 euro for an O/U. That's $428 U.S. dollars for your autoloader or pump, about $537 dollars for three choke tubes for your stackbarrel. In the United States, some want to buy the entire gun for that, or less.

No drop-in aftermarket choke tube, no matter how carefully made, can correct for a factory installation issue. For that reason, Jones suggested acquiring a fixed choke factory gun, then sending it to Mr. Teague for both precision thread installation on the barrel, then chokes matched to the exact bore size of the individual shotgun. I'm not at all taking issue with Andrews Jones' suggestion, nor with the well-known work of Mr. Teague. Quite the contrary, in fact. The best aftermarket choke makers have to compensate for factory tolerances, particularly the undercut where the choke mates with the barrel. To not do this would mean a lot more folks shooting out their choke tubes or permanently damaging the skirt area. A precise skirt to barrel fit means a cleaner choke, the sole attraction of fixed chokes, as no skirt or joint is present.

Factory choke tubes are often poor, both poorly machined, made of unknown metal, and mismarked or mismatched as to constriction. They are also typically weak, as you can tell from the “Lead Shot Only” warning stenciled right on them. Americans refuse to pattern their shotguns and gun manufacturers are well aware of this. If you don't pattern your shotgun, all kinds of things seem like they might work similarly, you'll never know. The highest quality for the absolute cheapest price doesn't happen very often, but when factory choke tubes are simply nameless “vendored items,” they are often acquired solely on the basis of low, off-shore, Asian acquisition price. The problems that Andrew Jones noted are to be expected.

THE DENSEST POSSIBLE PATTERN IS USUALLY NOT THE MOST EFFECTIVE

How often have you heard that a pattern was “perfectly centered” on a game bird or a clay target? It doesn't happen. If you look at a circle or a pattern, only one miniscule point is the center. Everything else is not the center. Pattern offset is unavoidable, the question of how much is not discernible by the naked eye. That there is pattern offset is well-known and well-documented. It varies in concert with range and in concert with the biggest variable of all: the human shooter and his skill and ability. It is for this reason that the densest possible pattern is not the most effective one. If pattern core density was all that mattered, it would be common to use turkey chokes on the skeet field.

The most useable pattern is not the absolute densest at all, it is maximum effective spread at the ranges we are shooting at that is what is sought. That's why we have to pattern, for effective spread varies based on game, clay size and target presentation. The forgiving friend of a .010 in. constriction pattern hunting doves around waterholes may be a crippling, ineffectual disaster for pass shooting at 50 yards. Tuning the maximum effective spread for an application is a continual process, but the more we pattern and the more we practice the easier it becomes.

ADDITIONAL READING

The best available version of the truth is often boring. For further reading, see The Mysteries of Shotshell Patterns by George G. Oberfell and Charles E. Thompson (1957) and the beautifully hardbound Hodgdon Powder Shotshell Data Manual (1996). The best general reference work on firearms to appear in many years is Firearms, The Law, and Forensic Ballistics, 2nd Edition by Tom Warlow (2005). For unequaled pattern analysis, with focus on clays applications, get Sporting Shotgun Performance by A. C. Jones (2010). Don't forget to read everything you can get your hands on by E. D. Lowry.