Charles Askins “The Cone”
Field & Stream, Nov. 1921
https://books.google.com/books?id=UP...J&pg=PA700&lpg
W.A. King for Parker Bros.
Referring to the cone, we ordinarily permit our shells to lap into it 1/8-inch, but as a matter of fact we have found that the majority of guns will shoot a better pattern with even more lap than this. In fact, we can secure extra good patterns by shooting extra long shells, permitting the lap to extent to the point where we begin to tear off the ends of the paper. At that point we do not seek to give more lap. In user’s hands we do not advocate the use of longer shells than those which give 1/8 lap.
As regards the shape of the chamber cones, we have tried very long taper cones, short, abrupt tapers, and now use on of a certain standard length, which is nothing but two reverse curves, easily run from the end of the chamber and as easily curved into the bore proper. When the tools are kept up so that these curves are correct, we consider that we have a properly shaped cone, and one that does no harm whatever to the shooting or patterning of the gun.
TPS no doubt has an engineering drawing for Parker chambers. The standard cone length for other U.S. makers was about 1/2".
Recognizing the shells then were roll-crimped and were (long) before plastic wads, I suspect Bro. King would be unimpressed by the "modern" extra long cones
