| Gun Tips | By Tom Radde, Mayer, Minnesota

SHOT GUNS
(Published in Spaniels In The Field Fall 1992)

First let's describe the inside of most all Japan, Belgium, Italian, and American shotgun bores. (popular guns used in the Field Trial game) The chamber is parallel, which tapers down to the bore. That taper is called The Forcing Cone. The bore is again parallel, at the end of which, the barrel tapers down to the choke, that is called choke lead, then, finally, the very end of the barrel, the choke, should again be parallel.

The purpose of the Forcing Cone, is to provide a path from the end of the shell to the bore. The longer and smoother this is, the fewer deformed pellets in your pattern. The rounder the pellets, the denser the pattern.

In the past, the days of rolled crimped paper hulls, the forcing cone was very short. This was needed to keep the gas from escaping past the inefficient fiber wads. Also the shot had no sleeve or wad, so the bore diameter was usually very close to the inside diameter of the hull. Often, pre 30's, the forcing cone was just 1/16" long. The perfect Forcing Cone was a small step, aligned so that when the paper hull unrolled it met the very end of chamber. Ideally, it was then a straight shot into the parallel bore. As time went on the next shell was still paper, but had a folded crimp with the paper folding over to the center. The gun manufacturers made the chamber a little longer, and increased the length of the Forcing Cone to between 3/8" and 1/4" to accommodate the longer paper hull. However, the early folder paper hulls still had no shot sleeve. Soon after the first plastic hulls appeared, the shooters complained it was a step backwards, because they were like the old paper rolled crimp style, the shooters didn't like the cardboard over the shot wad making holes in the pattern. The first plastic folded crimp hulls still had no shot sleeve, or one piece wad/shot sleeve as we know today, and the Forcing Cone was left as is.

When the shot sleeves, and one piece wad/shot sleeves combos came into use, the patterns improved so dramatically, the forcing cones were still left as they were. The firearms engineers decided the improvement was from the protective shot sleeve and most everyone was happy with the performance. Except the Handicap Trap shooters. When a 50 M.P.H. target is traveling away from you, and is launched 27 yards in front of you, you need every pellet you can get to hit that 4" diameter target. Most of the Handicap Trap targets are usually broke at 45 to 60 yards away from the shooter. Add to that, the best score can win hundreds or even thousands of dollars, you can see why this calls for not only tight patterns, but efficient, consent, and even, patterns. The Trap shooters continued to alter the bores, chambers, and Forcing Cones of their guns in the pursuit for more efficiency in their patterns.

One of the many things the experimenting Trap shooters found is, if you gently squeeze the shot down to the bore size, (longer forcing cones) you will again have less deformation of the shot pellets. Less deformation, less flyers, more consistent pattern. Another side effect of a long forcing cone is less recoil, a factor in trap shooting, where one may shoot hundreds of rounds in one afternoon. Almost all the Belgium Brownings, Japan Brownings, Berettas, Japan Winchesters, S.K.B.'s, and like guns have forcing cones from 1/2" to 3/4" long, and almost all those guns can benefit from a 1-1/2" to 3" long forcing cone and larger diameter bore, or back boring from the factory! More on back boring in the next article.

While a quality `back boring' job costs around $125.00, a quality Long Forcing Cone job costs, around $35.00

In the quest for a denser, more even pattern, the second step, behind checking out your chokes, is the long forcing cone. Just a small increase in the percentage of pellets placed on target can make quite a difference between a crippled runner and a clean hit.

Tom's fascination with guns started when he was 9 years old. He would go to farm auctions with his father and buy old rusty guns, take them home, clean them up, then take them to the next auction and re-sell them. Tom has been buying and selling guns for almost 30 years now. He currently owns a small gun shop in (downtown) Mayer, Minnesota where he deals in mostly Hinge guns.