Stock dimensions were aimed to fit the "standard" man.
But
Smith shooter Jack Fanning on L was short.
Smith shooter Wm. Crosby next to him was tall.
The other fellas were "standard" c. 1900
Men today are slightly taller, but much heavier, with a thicker face, chest, and waist.
A thicker chest increases the effective length of pull; a thicker face moves the eye upward from the comb and away from the rib.
24 year old Union soldier in 1860 - 5’ 8” and 143.5#
22 year old American soldier in 1955 - 5' 8" and 150.2#
50th percentile for American 25 year old men in 2002 - 5’ 10” and 168#
All US men 20-74 years in 1960 - 5’ 8” and 166.3#
All US men 20-74 years in 2002 - 5’ 9 1/2” and 191#