Trap guns are shotguns designed for shooting clay pigeons. The typical American trap gun is a single-barrel or double-barrel 12-gauge model. Trap gun stocks conform to the shooter's shoulder and face in specific ways to influence eye position and aim. This is accomplished chiefly by adjusting the comb, the portion of the stock on which the shooter's cheek rests. Adjustable combs provide both up/down and left/right adjustment. A stock of the correct length with a properly adjusted comb allows the shooter to see straight down the rib of the shotgun. Adjustable combs are standard on many trap guns or may be added to existing stocks.
Take the trap gun to a shooting range. Fire one shot at a shotgun pattern board from a distance of 30 yards. A tight choke should be installed on the barrel.
Evaluate the pattern produced by the shotgun pellets on the pattern board. Trap guns should aim high at approximately an 80-20 ratio: 80 percent of the pattern should be above the aim point on the pattern board and 20 percent below it.
Alter the vertical impact of the pattern by adding or subtracting plastic spacers supplied with the adjustable comb. Raising the adjustable comb raises the impact point and lowering the adjustable comb lowers the impact point.
Move the point of impact horizontally by loosening the comb posts and sliding them in the direction of the desired change.
Fire another shot at the pattern board. Evaluate the results and make additional adjustments to the comb as necessary.
Gus Stephens has written about aviation, automotive and home technology for 15 years. His articles have appeared in major print outlets such as "Popular Mechanics" and "Invention & Technology." Along the way, Gus earned a Bachelor of Arts in communications. If it flies, drives or just sits on your desk and blinks, he's probably fixed it.