A system was developed to standardise the method of specifying chokes and this resulted in a classification of five choke descriptions. The English system was logical and easy to follow, with the chokes designated: Full, ¾, ½, ¼ and cylinder. The Americans came up with their own system, with the designations: full, improved modified, modified, improved cylinder and cylinder.
The Europeans, just to be different, have a system of using asterisks or punch marks, starting with * for full choke, ** for ¾, *** for ½, **** for ¼ and CL for cylinder.
The interesting thing about choke designations relative to barrel dimensions is that the true measure of a choke’s designation is classified by how many pellets (as a percentage of the total in the cartridge) will fall in a 30″ (76cm) circle at 40 yards (36m).
Thus, a full choke gun may shoot a ¾ choke pattern with a particular type of cartridge and load. The development of special cartridges and wads (such as spreader wads designed to widen the pattern) gives the shooter a great deal of control over what happens to the shot if the principles are understood.
When skeet shooting was developed after WWI in the USA, a skeet choke designation was introduced, which is a cylinder choke with a very slight constriction (about 0.004″). While this level of choke did not significantly tighten the pattern, it made the shot distribution in the pattern more uniform.
Very few shotgunners take the trouble to pattern their guns. Serious clay target shooters are usually the exception. Most clay target clubs have pattern boards available. Some chokes may not deliver uniform patterns while others may not deliver the shot pattern to the point of aim. Some guns may prefer a particular batch or brand of shotshell.
Rifle shooters will always sight their rifle before going afield and shotgunners should do the same to find out how the chokes are performing with the selected loads, and equally as importantly, where the centre of the pattern is falling.
Sometimes changing chokes may change the point of impact and shotgunners need to know about such things to avoid unnecessary disappointment.
Selecting the right choke for a particular job is also partially determined by the shot size involved. For example, using 9-shot in a full choke barrel will produce a very dense pattern with a large number of very small pellets, which do not have much energy left after 35 metres. This is contrary to conventional wisdom in using full choke barrels.
If all your shots are less than 30 metres, you don’t need a full choke. If you are shooting at aerial targets no closer than 45 metres, only a full choke will do the job. Larger shot sizes are best used with tighter chokes because of the lesser number of pellets in the pattern, just as small shot is best used in more open chokes as the pellets are so light that they will be ineffective at longer ranges anyway.
Pattern at 36 Metres
Pellet count for various shot sizes
|Shot Size||9||8 ½||8||7 ½||6||5||4||2|
|Pellet count – 28gm load||585||485||410||350||225||170||135||90|
|Pellet weight grains||0.75||1.07||1.10||1.25||1.94||2.57||3.24||4.87|
|Pellet diameter (mm)||2.30||2.16||2.29||2.41||2.79||3.08||3.30||3.81|
What Experienced Shotgunners Say…
2, 3 *
|Modified–for pass shooting
Improved Cylinder–over decoys
|Use BB shot for long range and pass shooting. For normal range–No. 1 or No. 2 shot while some hunters use No. 3 shot for closer range shooting over decoys.|
BB, 1 *
|Modified||Goose hunters need wallop so they use the big loads with large shot. Many hunters prefer No. 1 shot for a denser pattern at shorter ranges over decoys.|
|Pheasants||5, 6, 7½||Improved Cylinder–for close cover
Modified or Full–for long cornfield shots
|For cornfield shooting where long shots are usual – better use No. 5. On a normal rise over dogs and for all around use, No. 6 is the favorite.|
|Grouse or Partridge||5, 6,
|Improved Cylinder or Modified–for brush work
Full–for open ranges
|On the smaller birds such as ruffed grouse or Hungarian Partridge, use the smaller shot. The big western grouse (sage, sooty, and blue) call for heavier loads and larger shot.|
|Quail||7½, 8, 9||Cylinder
|For early season shooting on bobwhites when feathers are light, some hunters use No. 9 shot. Later they switch to No. 7½ or 8. On the running or wild flushing type of quail, such as the Gambel’s, large shot is sometimes used.|
|Doves and Pigeons||6, 7½,
|Use lighter loads and No. 7½ or No. 8 shot on mourning doves at normal ranges –for longer ranges use the heavy loads and No. 6 or No. 7½. Use the same load on band tailed pigeons and white wings.|
|Woodcock||7½, 8, 9||Improved Cylinder
|The choice of shot size here will depend on ranges at which the game is shot. For fast shooting in the alder thickets, No. 8 shot is a good choice.|
|Trap||7½, 8||Full or Modified||In most cases, No. 7½ is used for trap. Check the Official Rulebook.|
|Skeet||8, 9||Skeet Choke
|In most cases, No. 9 is used for skeet, check the Official Rulebook.|
|Sporting Clays||7½, 8, 9||Any choke (Depends on practice desired)||For targets at close range use a more open choke, at longer distances tighten the chokes.|