Shotguns are short range weapons. Shotgun enthusiasts learned long ago they can increase the distance by introducing a slight tapering constriction at the muzzle end of their gun barrel, called the "choke." the choke constriction deflects some of the pellets back towards the middle of the cloud of shot, minimizing the amount of scatter and increasing the pellet density of the cloud over a longer range. Choke works the same with either lead or steel shot. but because of the difference between lead and steel shot, the results are different.
Normal Chokes
Shotguns got the nicknamed "scatterguns" because of how quickly the shot pellets fired from those with no choke would scatter. Non-choked guns deliver their optimum pattern at less than 20 yards. Shotguns with only a slight amount of choke are called "improved cylinder," and their optimum pattern occurs at 25 yards. A fully choked gun with a lot of constriction is still effective at 45 yards. An intermediate choked gun, called a modified gun, delivers a good shot pattern to 35 yards. There are numerous constrictions in-between these two chokes which might measure only a thousandth of an inch more or less. Improved-cylinder, modified and full chokes are the three most commonly used.
Round Flies Straight
The main factor which determines how straight a shotgun pellet will fly is how perfectly round it is. The more oval its shape, or the more dents or flat spots on the pellet, the greater the amount it will curve as it travels downrange. Lead pellets are relatively soft. The almost instantaneous acceleration from zero to more than 1,300 feet per second slams the pellets together, denting and flattening them from an oval to an egg shape. Hard steel pellets are much less likely to dent, flatten or deform, so they tend to fly straighter than lead pellets.
Choke Rules
Since steel pellets tend to naturally fly straighter than lead pellets, less choke constriction is needed to produce an optimum pattern at the range you expect your targets to be presented. A rule of thumb is if you normally use a modified choke with lead shot, switch to an improved cylinder choke when shooting steel. If you normally shoot a full choke, switch to modified. Choke tubes with zero taper are available for steel pellet shooters who normally shoot improved cylinder choke when firing lead.
Pattern Test
Regardless of whether you use lead or steel shot, fire some test shots at the range to find out how lead and/or steel shot shoots in your shotgun. Look at the density of the shot holes in the paper. If there are many places where your target could have escaped being hit, you need to use a tighter choke. If there are so many pellets close together, use less choke and allow the pattern to spread out more quickly.
References
Writer Bio
Mike Schoonveld has been writing since 1989 with magazine credits including "Outdoor Life," "Fur-Fish-Game," "The Rotarian" and numerous regional publications. Schoonveld earned a Master Captain License from the Coast Guard. He holds a Bachelor of Science in wildlife science from Purdue University.