“Another Two Grams, Sir?”

It is undeniably true, that a single pellet of non-uniform shape and substantial proportions, conveniently loaded into a cartridge labelled “.460 Weatherby” with appropriate charge of powder will – if aimed accurately – kill basically any creature on earth. In retrospect, we might refine that to “land-walking creature”: whether even Weatherby’s elephant-killing cartridge would put a hole through – for example – a blue whale, remains unclear, but I’ve no doubt it would have a pretty good go.

Nonetheless, if we forgo the single-projectile approach of rifled barrel and jacketed bullet (and before them, the smooth bore musket and lead ball), we must rely on a charge of many shot propelled at sufficient velocity, to impact and kill our quarry.

This approach too, can be taken to absurd extremes: why not simply buy a tube big enough to pack in a hundredweight of .57 calibre lead balls and the powder required to propel them and project them towards our quarry, big or small? One of them will surely impact it – whatever “it” is – and knock it flat!?

No – amusing as the idea may be in its preposterousness, this article has been written to consider the dull, reasonable case and answer head-on the fallacy oft-repeated by experienced but ignorant game shooters and gunwriters who, frankly, should know better. It goes something like this:

“At the start of the season, I’ll use a cartridge with 28g or 30g of #6 or #5 shot, but for January cock pheasants, I like a little extra in the cartridge and change up to 32g.”

Sound familiar? Have you too been using a heavier cartridge for your January birds?

Dealing With Doubt

I’ll put my cards on the table straight away. I am not an experienced driven game shot, so my credentials in that respect are not particularly good. However, I have shot a good number of other birds in the course of my shotgunning “career” and I do know a thing or two about the behavior of ammunition – particularly where shotgun cartridges are concerned. I also know a thing or two about not having confidence when shooting. I will always be the first to say that, if you are not absolutely certain in your mind that your cartridge will do its job if you do yours, you cannot and will not shoot to the best of your ability. That nagging voice that asks “is the kit I’m using really up to it?” at the back of your mind has already done the damage by the time you hear it.

Generally, human beings have three ways of dealing with problems. They either try to understand and solve them, ignore them, or run away from them. All of us use all three options interchangeably, dependent on our situation and character.

Although it does happen that, where a genuine lack of ability or overwhelming frustration confounds them, a shooter will simply give up shooting, sell their kit and walk away from the sport, it is uncommon. The investment required to shoot any kind of game in this country is high, and shooters – particularly shotgun shooters – therefore tend to take one of the former two options when addressing the question of what will improve their standard of shooting. This is never more true than in choice of cartridge.

In response to the question “what shells are you using?” you’ll often hear the answer “ones that go bang”. On one level, this is admirable. It’s true that, in most shooting situations, most commercially-produced shotgun shells will “out-shoot” 99% of the people who use them. Where the small bores are concerned, this is perhaps marginally less true: the very small gauges introduce or amplify certain characteristics of shotgun behavior which even the most talented manufacturers of ammunition cannot fully overcome, but the value of simply not caring what kind of ammunition one is using to calm, controlled shooting should not be underestimated.

Regardless, anything that interferes with the instinct, honed through practice, that makes us simply “know” that holding and swinging the gun in a particular way will allow us to successfully shoot a bird of a particular presentation is likely to be detrimental to the act of doing so. Thinking is – in short – fatal.

The Scientific Approach

There are some of us however, for whom a simple, unthinking approach will not suffice. We are too enthusiastic about our sport to allow our minds to be closed to the technical details of shooting – there is too much to experiment with and understand.

Many folk would respond that we simply want to have our cake and eat it. We (unreasonably) expect to be able to know everything about how a cartridge can work (or fail) and still hold our nerve to break the deciding clay in the Skeet World Championships. Perhaps, though, we never expect to find ourselves in that situation and therefore the intellectual challenge, followed by understanding, gives greater satisfaction?

Each to their own, but the intellectual approach does bring with it one advantage: the ability to spot and refute ridiculous, patronizing “advice” (most people call it something rather ruder – Ed.), often given with the best intentions (or repeated unthinkingly), but which ultimately serves only to confuse the majority and enrich the few well-positioned to take advantage of their ignorance.

Read again the advice quoted in the first section of this article and ask yourself the following questions:

  • Why, at the time of writing, does a major UK supplier of shotgun cartridges list a “pigeon”-type cartridge, containing 30g of #6 shot for a little over £6 per box, whereas the cheapest 32g/#6 cartridge from the same manufacturer costs just shy of £9 / box?
  • Does the extra 2 grams of lead shot in the £9 cartridge really justify the £2.60 price increase?
  • Is a performance benefit of – we assume – around 7% more shot really great enough to justify a 41% increase in cost?

Let’s find out.

Some Numbers

Let’s use the examples above and some reasonable approximations to calculate the theoretical usefulness of those extra 2g worth of pellets. We’ll start with that 30g load of #6 that our imaginary gunwriter suggests for early-season pheasant and calculate from the widely accepted figure of 270 pellets per ounce, that there should be somewhere in the region of

[pel./g #6] = 270 [pel./oz] / 28.35 [g/oz] = 9.524 pellets per gram
[pel. 30g of #6] = 9.524 [pel./g] * 30 [g] = 285.72 [pel.]285 pellets

in the cartridge. Let’s compare that to the number of pellets in the 32g cartridge:

[pel. 32g of #6] = 9.524 [pel./g] * 30 = 304.77 [pel.]304 pellets

So, the extra two grams of shot give us approximately 19 extra pellets in the shell.

Now let’s think about the situation our gunwriter is describing. He’s comparing the cartridge requirement for early-season and late-season pheasants. Obviously, it’s hard to predict the precise effects of a cloud of pellets impacting a moving bird except by testing empirically, but happily, our forebears, using the combined experience of over 100 years of shooting shotgun shells loaded with smokeless powder, have come up with some reasonable approximations.

The first approximation is the good old “standard circle” of 30 inches diameter. The theory goes that if your cartridge puts enough pellets into a 30″ circle drawn on a piece of cardboard when shot at the range you intend to shoot, it should also kill your intended quarry. Of course, the number of pellets required depends on the size of the quarry, but here it doesn’t actually matter – what we’re interested in here isn’t the number of pellets, but a sensible approximation of the size of the effective part of a pattern. The 30″ circle is widely used, so we’ll use it too.

The second approximation is the 5-inch circle, used to represent a game bird. The origin of this approximation isn’t clear to me, but the theory is that the vitals of a medium-to-large game bird will present a target approximately 5″ in diameter. Therefore, to have an effective overall pattern, one ought to have in it as few areas as possible where a 5″ circle can be drawn that does not contain a single pellet impact. A pattern with none of these areas is a pattern through with a bird cannot escape if the shot is broadly on-target.

So, how do those numbers help us?

Allowing for the several approximations we have clearly made, we can calculate a value for pattern density‡ for each of the cartridges described above and compare the number of pellets we expect to be in each “bird-sized” area (i.e. 5″ circle) to see what difference those extra 19 pellets might make to our cartridge’s effectiveness.

Let’s say that our imaginary test gun achieves a standard “Modified” performance, representing 60% of the available pellets falling within the standard circle at a distance of 40 yards, with both cartridges. Therefore:

[30g cartridge pel. within 30″ circle] = 304 [pel.] * 60% = 171.0 pellets
[32g cartridge pel. within 30″ circle] = 304 [pel.] * 60% = 182.4 pellets

Now we divide the area of the standard circle by the area of the 5″ circle to discover the ratio between the two areas.

[Area of a 5″ circle] = π * (2.5 [in])² = 19.635 in²
[Area of a 30″ circle] = π * (15 [in])² = 706.858 in²
[5″ circle areas in 30″ circle area] = 706.858 [in²] / 19.635 [in²] = 36.000

Finally, we divide the number of extra pellets which fall in the circle from the 32g cartridge by the number of 5″ circles. This represents the average number of pellets which will impact each 5″ circle, over and above the equivalent value for the 30g cartridge.

[Increase in avg. impacts per 5″ circle] = 11.4 [pel.] / 36.000 = 0.31666 extra impacts


So what does all this mean?

Remembering that this simply an example based on reasonable but necessarily simple approximations, a useful way of expressing our “headline figure” above is as a probability.

If each 5″ circle has, on average, 0.31666 extra pellet impacts when an extra 2g of #6 shot is added to the cartridge, then we can equally say that, with a 2g increase in shot charge, we expect to achieve 1 extra pellet impact in any randomly-chosen 5″ circle, 31.7% of the time.

Another way of expressing that is to say that the extra weight of shot will have no effect whatsoever on whether or not the bird is hit and killed, for two out of every three cartridges fired.

Yet another way to look at this is to ask “how much extra shot do I need to guarantee that the bird will be hit by at least one more pellet, anywhere in the pattern?” The answer to that question can be calculated straightforwardly, by multiplying the reciprocal of our increase in average number of pellet impacts by the weight of shot which achieved it:

[Extra Shot Required] = (1 / 0.316666) * 2 [g] = 6.316 grams

Not until we load the cartridge with over 36 grams of (#6) shot do we make it a statistical certainty that we will achieve one more hit on the bird than with the 30g cartridge! Many people’s shoulders would feel sore just at the thought of banging away with 36g cartridges all day long, though I won’t argue against the practice if you can stand it – it’s the traditional 12 gauge game load.

Returning to some earlier figures, we can also calculate the relative increase in pattern density as a percentage improvement in performance. We can ask “what improvement in performance is required to make the 30g load give equivalent performance to the 32g load displaying 60% performance?” This is a simple calculation:

[Percentage Improvement Required] = (182.4 [pel.] – 171.0 [pel.]) / 171.0 [pel.] = 6.6667%

Compare that with the 10%+ improvement in performance which can often be achieved quite straightforwardly with an one-step increase in choke constriction and we can legitimately ask whether adding extra shot should be first port of call when an improvement in pattern density is required. In the age of the ubiquitous multi-choke, I suspect perhaps not.


So there you have it. Our imaginary gun writer is clearly off his rocker if he believes that 32g of #6 shot will noticeably improve the results of his shooting over 30g of #6. It may make a tiny difference, but it is unlikely to be detectable, in the field, to the average Gun.

Admittedly, the manufacturers are not always guilty of profiteering with the sale of game cartridges at – in places – twice (or thrice) the price of near-identical “clay” or “pigeon” shells, though there are some particularly egregious examples of inflated RRPs at the time of writing.

To give them the benefit of the doubt, loading machines, usually configured to produce batches of tens or hundreds of millions of clay cartridges are expensive to re-tool to produce smaller batches of game cartridges numbering only a million or two. Human intervention in any process carries the cost of wages, which makes any product requiring more frequent intervention more expensive. In a highly competitive market, the manufacturers will not survive unless they cover their costs and, historically, game shooters have had – on average – bigger pockets than most.

The quality of components may indeed be better in more expensive cartridges and they may tend to improve performance. However, there are myriad variables that the manufacturers cannot control, not least gun and choke, and the idea that the average shooter can – without determined effort – tell the difference between plain and copper-plated shot, or one kind of wad or another, for example, defies belief.

Ultimately, the market stays afloat on the willingness of consumers to pay for a brand that they trust and which gives them confidence, whether or not the performance of the cartridge justifies its extra cost over often equally-performant alternatives.

Of course, an increase in shot size may justify a small increase in payload if one simply cannot stand the higher recoil associated with maintaining pattern density in that larger size. All other things being equal, one needs – for example – about 39g of #5 shot to give the same pattern density as 28g of #6. This represents quite an increase in the thump to the shoulder, even with the smoothest cartridges available and one that most shooters would not tolerate.

In most cases, however, any sensible “pigeon” or “game” cartridge will do everything an ordinary Gun asks of it. Even the lowly ounce of #6 will bring down most birds as far as 50 yards away if the gun has a bit of choke and patterns well. Most game cartridges in 12, 16 and 20 gauges exceed by a large margin the bare minimum requirements for the killing of game at all reasonable ranges and it is usually reasonable to assume that a miss with these cartridges is the fault of the shooter and not of the cartridge.

Exactly what constitutes the minimum loading for shooting game is a question dependent on maximum intended range, type of quarry and to a limited extent, the gauge of gun used, but for general purpose use, is likely to be somewhere between 14-21g of #7½ or #7 shot. A future article exploring this question is currently in the planning stages.

† = I remind readers that 32g, better known then as 1 1/8oz, used to be the bog-standard, “low brass” load for the 12 gauge, before we all swallowed the lie that “speed is king” – but that’s another story.

‡ = The value for pattern density calculated here is a linear pattern density. As readers may be aware, pellets are more often approximately Normally distributed in shotgun patterns, which makes this model somewhat basic. However, although that is the case, I encourage the thoughtful reader to consider whether the extra pattern density afforded by the extra 2g of shot in the imaginary cartridge will make any difference even if a Normally distributed pattern is modeled. I propose that, in the center of the pattern, it is extremely unlikely that an extra pellet in any given 5″ circle will produce a noticeable effect given the already higher-than-average pattern density. On the outside of the pattern, an occasional lucky strike may account for an extra bird in the bag, but I defy anyone who cannot identify the cartridge being used to tell the difference.