WINCHESTER Model 21
Bore and Choke Specifications
GAUGE |
BORE DIAMETER |
CHOKE |
% in 30" Circle @ 40 yards * |
CHOKE DIAMETER |
CONSTRICTION |
12 |
.730" .005" |
Full |
65% - 75% | .694" - .699" |
.031" - .036" |
Imp. Mod. |
55% - 65% | .712" - .715" |
.015" - .018" |
||
Mod. |
45% - 55% | .715" - .720" |
.010" - .015" |
||
Imp. Cyl. |
35% - 45% | .724" - .726" |
.004" - .006" |
||
16 |
.670" .005" |
Full |
65% - 75% | .640" - .645" |
.025" - .035" |
Imp. Mod. |
55% - 65% | .652" - .655" |
.015" - .018" |
||
Mod. |
45% - 55% | .655" - .660" |
.010" - .015" |
||
Imp. Cyl. |
35% - 45% | .664" - .666" |
.004" - .006" |
||
20 |
.615" .005" |
Full |
65% - 75% | .590" - .595" |
.020" - .030" |
Imp. Mod. |
55% - 65% | .600" - .603" |
.012" - .015" |
||
Mod. |
45% - 55% | .603" - .608" |
.007" - .012" |
||
Imp. Cyl. |
35% - 45% | .609" - .611" |
.004" - .006" |
* Figures from "Winchester Gun Salesman's Hand Book" ©1949
©2010, M.C. Manges