Friends All....Hardly a week goes by that I don't get an email asking about the latest fad....lengthening forcing cones.
Let's first cover just what is a forcing cone in your shot gun and why it is there. The forcing cone is the tapered portion in the inside of the barrel ahead of the chamber. This taper allows the shot column to funnel into the barrel. Today's shooter, listening to all the hype, is directed to lenghten (less abrupt taper) in order to reduce shot deformation and recoil. This is nice, if you say it fast!
Without being too technical, let's move ahead to the meat of this post. Until very recently, shotguns made overseas had a very short forcing cone. This was due to the fact that shotshells without one piece wads were used more overseas. These stacked wad columns, many with the old hard cardboard "nitro" over powder wad, needed to seal quickly to reduce blowby. These short forcing cones are still best for the loader making up specialized long range loads with stacked wad columns and heavy shot payloads. There may. and I do say may, be some advantage to the clay bird shooter...not so much for shot deformation, as for the little bit less recoil (fatigue factor in a 100 bird race?)
So....Think about it before your lengthen that forcing cone if you shoot field loads with stacked wad columns. You may just be asking for blowby! James C. Gates

__________________
Dixie Slugs of Old Town Hammock, Florida
"Home of the Dixie Terminator Slug"

Hi, Mr. Gates:
I should tell the crew about a minor reloading mishap I had this summer with stacked wads. Year ago I loaded C-I-L 20 gauge cases with Federal fiber wads and a Lee Loader. I tried them again this summer, only I used the Mec Sizemaster, set up for Winchester cases and WAA20 wads. The wads took excessive pressure to seat. Ok, Einstein, the petals on the WAA20 wad effectively reduce the inside diameter of the case, therefore, the fiber wad column has to sit higher for the same shot volume. I adjusted the rammer tube and loaded the rest of the box without problems. I patterned the first shell, broke the gun open without looking and the shell felt funny. I was holding the brass shell base in my hand and the plastic tube was still in the barrel The wad was rammed into the tube so tight it pulled the tube from the base.

The rest of the box shot without a problem and smoked clays nicely. Many of the shells we reloaded with the little Lee were fired in an autoloader, which will pull bases if anything will, but even a gorilla couldn't apply the wad pressure with a Lee that a MEC can.

Moral, loosen the rammer tube clamp before you try a new wad and/or powder. You can always add pressure later.

Bye
Jack