“Pattern plates are the one thing that drives me crazy. You see people walking up there with boards and paper - when I go to a competition, call pull and a pattern plate comes out I’ll start to shoot them. Until then I’ll stay away from them.” So says Ben Husthwaite, one of the most successful clay shooting coaches in the country. His recipe for success has been tested in top level competition using the same cartridge and gun combination for many years. But is he right to advise us to ignore the pattern plate? Choke is one of the ingredients we test on a pattern plate. Simply put it is the narrowing of the barrel at the muzzle end that constricts the shot cloud as it passes through. The point Ben is making is that those who do not understand the process of pattern testing should not obsess over what maybe the result of poor methodology as it can sow toxic seeds of doubt. He does however test cartridge choke combinations on behalf of some of his clients in the same way that the gunmakers of old would regulate a barrel to a specific weight of shot and powder for a specific range.

CHOKE ORIGINS
It was developed as a concept in the later half of the C19th during the maelstrom of gunsmithing invention both here in the UK and in America. Patents for choke boring were applied for in 1866 within six weeks of each other by the American Sylvester Roper and by William Rochester Pape of Newcastle. The great self-publicising gunmaker W.W. Greener however did the serious marketing of choke and brought it to wider attention during the London Gun Trials many of which he won.

BARREL & MUZZLE

The degree of choke in your gun barrel is the difference between the size of the bore (the barrel diameter) relative to the constriction at the muzzle. For this reason, plug in choke ‘gauges’ will only ever give you a very rough guide. The only way to measure choke accurately is with a bore gauge of the type gunsmiths use to measure bore diameter when checking if a gun is in proof. When buying second hand guns if a barrel has had any pits bored out of it and been reproved as a result, this will alter the choke measurement without the choke itself being altered. The relationship between barrel and muzzle is one that matters.

DEGREE OF CHOKE

Choke itself is measured in thousands of an inch usually up to 40 thou. Every 5 thousands of an inch in a 12 bore is one point of choke. Normal chokes are given in eighths. 20 thousands of an inch between muzzle diameter and barrel diameter would therefore be 20/40, 4/8ths or 1/2 choke. It is referred to differently in different countries but I prefer to measure in eighths.

The technical aspects aside, the question before us is ‘does it matter’. The answer is ‘up to a point, yes’. The reason for the slightly cryptic answer is it is down to you to find out how your particular combination of ingredients works for you. You cannot find out on the internet how your cartridge performs with your barrel and choke combination. You must use a pattern plate or better still have someone who has a detailed understanding of the tedious process of pattern testing do it for you. If you are determined to do it yourself BASC has an excellent guide available on how to pattern test properly but the headline from it is you must use at least 10 cartridges through the same gun and choke to get a big enough sample to get the complete picture. It will probably surprise you just what more open chokes are capable of. You may be shocked at how large gaps can appear in some extremely tight chokes too.

MODERN MULTICHOKES

Multichokes for double barrelled shotguns are a relatively recent invention. The first was the ‘Winchoke’ developed by Winchester in the 1970’s. Multichokes have now become commonplace and companies such as Teague Chokes will retrofit multichokes to any gun of your choice as long as there is enough metal to work with (which is not always the case). they also offer a barrel regulation service to a specific cartridge and distance. The benefit of Teague thin walled chokes is they do not alter the balance of the gun greatly. Some guns have the option of a multichoke or a fixed choke version.  Factory multichokes can feel muzzle heavy compared to their fixed choke versions, as factory screw in chokes tend to be much thicker steel lying at one end of a fulcrum, like a heavy weight on a seesaw. Clearly the great benefit of the development of the multichoke is the recipe became much more adaptable and for sporting clay shooters they could change it according to the targets they were facing.

NOT ALWAYS HELPFUL

This is not always a benefit. Agonising over what the best choke for a particular target can lead to indecision and distraction when you should just get on and shoot the bird. The best performers both clay and game, understand that reducing the variables in the recipe can help with the all important ingredient for good shooting – confidence. One of the very best, Olympic Gold Medallist Richard Faulds said “personally I’ve used Express cartridges and full and full choke for over 20 years now, but to be honest when you compare the breaks that Tanya [Faulds] gets with improved cylinder [1/8th] that she uses all the time you can hardly tell the difference. It’s all down to confidence and what works for you.”

Choke certainly does matter when using steel shot for shooting wildfowl. Again, BASC’s guidance sheets are invaluable. You should not use standard steel loads in nitro barrels with tighter than half choke. High Performance steel loads should only be used in HP steel proofed barrels and no shot sizes bigger than BB should go through tighter than full choke. (This guidance is new and was updated by the proof houses March 2020) Steel pellets are harder than lead and they do not deform when passing through a constriction. Because of this, ring bulges can occur if too tight a choke is used with large steel pellets. Shotguns rarely blow up, but ring bulges can ruin the performance and value of a gun. You can use smaller steel (7.5) shot designed for clay shooting through tighter chokes. However, steel patterns more tightly than lead as a rule, partly because it does not deform as it passes through a choke as lead does, and partly because it has to be used with a plastic wad. So tighter chokes may not be worth it and again it is up to you to find out on a pattern plate. If you have any safety concerns it’s worth talking to the manufacturer or to BASC.

CARTRIDGE CHOICE

The cartridge you choose to use through the choke you select can have an effect too. Some of the top end clay cartridges on offer can have a higher antimony content in the lead to make them harder, deform less during the vigorous process of travel down the barrel and therefore pattern better. Some of them are even plated shot which is designed to act as a lubricant between the pellets as the shot cloud moves down the barrel. Although it is commonly supposed that it makes the shot harder, plating alone does not. These top-level competition cartridges, designed to break that extra clay that separates the top of the leader board, also tend to be loaded with plastic wads. All of these factors can combine to throw tighter patterns through the same choke when compared to game loads with fibre wads and standard lead pellets. Although not a new idea, we now see copper plating being applied to top of the range game cartridges too.

FIBRE OR PLASTIC?

There has always been some argument as to whether fibre wads throw more open patterns than plastic wads, but as we have seen these questions cannot be solved by abstract debates. Your own experience matters far more than my experience. There are simply too many variables in the equation: barrel maker, length of forcing cone, bore diameter, choke profile, degree of choke to name some. When you add to that the range of different component parts that cartridge manufacturers use in their own products, you begin to see why shouting at each other on social media is hardly scientific. My own experience tells me that budget fibre wads cartridges may well benefit from the use of a slightly tighter choke in the same way that top of the range clay cartridges, almost all of which are plastic wadded, may well throw tighter patterns than you might expect. The difference is only really noticeable on the most testing of clay targets though but success or failure on these targets might separate the podium positions. Consumers like choice and manufacturers understand this. What we have to do as shooters is benefit from the experience of seasoned shots both clay and game, most of whom find a combination they have full confidence in and stick with it. That confidence can only be gained by finding out exactly what your chosen combination is doing by using a pattern plate. When you think about it shooting is an enormously complicated calculation: trying to hit a target 40 yards away, doing 40 mph, with a moving gun, throwing a shot column doing 900mph. When broken down like this it is a wonder we ever hit anything. (It’s interesting to note that the US Military had serious problems trying to get a missile protection system to replicate this calculation.) The trick is to simplify it as much as possible. This then allows nature’s most astonishing computer, your brain, to do the maths for you. When you remove as many variables as possible from the equation you can’t blame the equipment when you miss – it was working for you last week after all. Using a consistent recipe means you are far more likely to solve the problem by looking to your footwork, gunmount, timing and relaxation. The problem almost always lies in one of these areas. Does choke matter? As we have seen it is more complicated than that. Once you have found a combination you have confidence in, stick with it and leave the chokes alone.

FIRST PUBLISHED IN THE SHOOTING TIMES MARCH, 2019