History of Shotgun Chokes
History of Shotgun Chokes
Written by Peter Harris
Find any group of shooting men around a drinks table or a meal table and often the conversation will include 'Choke' and the vagaries of the mystic powers of choke.
Choke explained simply is a constriction to the shotguns bore at the shots exit end (the muzzle) a reduction of the bore size from its true bore size (nominally 0.729 for a 12 bore ) by a small amount normally measured in thousandths of an inch ranging from 0.005" up to 0.040" usually the maximum.
It is unclear who actually invented choke although many have claimed to and numerous patents have been granted. What we do know is that J.W. Long, in his book "American Wildfowling", credits a Jeremiah Smith of Southfield, Rhode Island, as the gunsmith who first discovered the concept, as far back as 1827. But many modern day Americans credit a gunsmith and wildfowler called Fred Kimble with using choke boring to win the Illinois State Championship on numerous occasions in 1868. But another American Sylvester Roper who was a friend of Kimble had actually applied for a patent in 1866.
But I think it is necessary to point out that the American and Pape's efforts were rather crude and the results were not often repeatable or quantifiable in performance terms.
It was not really a new dawn until William Wellington Greener was commissioned by a customer who described in a letter of instruction to Greener to produce a gun with choke boring (Did the customer travel to America?)
W. W. Greener's first intimation of the choke formation was derived from instructions given in a customer's letter, in early 1874. The customer's instructions described a choke, but did not give any details on the size or shape, or how it was to be obtained. Hence, Greener had to conduct many experiments to determine the perfect shape and size of a choke for a given bore.(These experiments continue today with the theories of the different choke borers /manufacturers all claiming that their profile is the best, Teague , Briley, Comp n Choke and Muller just being many of the different manufacturers all with differing theories and ideas.) After that, he developed tools to
produce the choke bore profile correctly and smoothly.
The system of choke boring that he pioneered was so successful that it was later adopted by other manufacturers and hence, some authorities give him the credit for inventing the concept, since his method became the first repeatable method of choke boring. It should be mentioned here that William Ford who was later to become a Birmingham gunmaker in his own right was known and indeed credited with boring the 'Field' Trial winning guns. Sadly it is alleged that Pape used illegally loaded cartridges to enhance his barrels performance.
In December 1874, the first mention of Greener's choke bore appeared in an article by 'Stonehenge' J.H. Walsh, the editor of Field magazine. The article mentioned the extraordinary shot pattern that the Greener shotgun could produce. The next issue came with an advertisement from Greener, stating that the firm would guarantee that their new guns would shoot a closer pattern than any other manufacturer. The advertisement claimed that Greener 12 bores were warranted to shoot an average pattern of 210, when the best 12 bore gun in the London Gun Trial of 1866 could only average 127. Naturally, the advertisement generated considerable controversy, especially from rival manufacturers of cylinder guns, who refused to believe the numbers quoted in the advertisement.
In order to resolve the controversy, the editors of Field magazine decided to conduct a public trial in 1875. The London Trial of 1875 pitted choke bores and cylinder guns of various manufacturers in four categories? Class 1 (large bores, any boring), Class 2 (Choke bores, 12 gauge), Class 3 (Guns of English boring or Cylinders) and Class 4 (Small gauges, any boring). The choke bored guns performed better than the cylinder guns in all these tests, and W.W. Greener choke bore guns won the class
1, class 2 and class 4 categories. Greener Choke bores also won at the London Gun Trials of 1877 and 1879, and the Chicago Field Gun Trial of 1879. The results of these trials were responsible for helping to make the W.W. Greener name famous, and for confirming the practical advantage of a repeatable method of controlling the performance of a choke on a shotgun.
It was not until 1959 that American gunmaker Winchester introduced the Model 59 Semi-Auto with a removable/replaceable choke sleeve into the muzzle, this was fraught with problems regarding performance and reliability but they persevered and in 1970 introduced the Model 1400 with the now famous 'Winchoke' which is undoubtedly the forerunner to modern day multichoke systems. But is there a 'magic ' choke constriction? Well they say beauty is in the eye of the beholder and surely choke is the opinion of the user.
What is certain is that to break a clay it is accepted that we need at least three pellets to strike the clay and probably 4-5 to mortally wound a bird.
For this we need a constriction (choke) that produces an effective pattern at the distance (range) that we engage the bird or target.
We would not necessarily need a Full choke to place 4-5 pellets in quarry at 20 yards (we would have far too dense a pattern). Conversely we would be struggling to have an effective pattern using 'Skeet' 0.005" inch constriction on a bird at 40 yards plus, the 'pattern' would have far too many gaps and holes in it.
Choke is nominally labelled and identified by the following names and level of constriction in the UK
- Cylinder which is the true bore of the barrel (no constriction)
- Skeet normally 0.005"
- 1/4 choke or Improved Cylinder 0.010"
- 1/2 choke 0.020"
- 3/4 choke 0.30"
- Full Choke 0.40"
A very good rule of thumb to use to select the correct choke is as follows.
- For 40 yards or more use Full Choke
- Up to 35 yards use 3/4 choke
- Up to 30 yards use 1/2 choke
- Up to 25 yards use 1/4 choke
- Less than 25 yards use Skeet
This selection will give you an adequately dense pattern at the range selected to cope with any target or quarry, all you have to do is position the muzzle correctly.