Not pattern % but pattern spread
Field and Stream Sept 1964. I do not have the original article but assume the shells were Winchester/Western Mark 5 with the polyethylene shot collar introduced in 1961. Modern loads are likely better.
…………………………………………YARDS………………………….
.....…….....10…… 15……20……25……30……35……40
CHOKE
Full…………. 9……..12……16……21……26……33……40 inches
Mod……..……12…….16……20……26……32……38……46 inches
Imp Cyl……..15…….20……26……32……38……44……51 inches
Cylinder……. 19……26……32……38……44……51……57 inches
Another
…………………….Approximate Pattern Diameter (Inches)
Choke
..........................10 Yards….......20 Yds….....25 Yds......30 Yds….....40 Yds
Spreader
..............................23............37............44............51............66
Cylinder
..............................20............32............38............44............57
Improved Cylinder
..............................15.............26............32............38............51
Modified
..............................12.............20............26............32............46
Full
...............................9.............16..............21............26...........40
