Here I am -- wharrison is correct to the best of my knowledge. It came with a snap-on shroud ... most did not like it stating it detracted from the sight picture and removed it .. IIRC, there were some issued to the Marines that were not a snap-on and could not be easily removed.
My data books state the following:
Remington made mostly 4-groove barrels through about 5-43. Remington made mostly 2-groove barrels after 5-43.
Smith-Corona made mostly 6-groove barrels through about 2-43. Smith-Corona made mostly 4-groove barrels after 2-43. Smith-Corona made a very few (rare) 2-groove barrels in 11-43.
However, there seems to be many, many exceptions.
The number of grooves was changed to increase production through-put and reduce cost.
My data books state the following:
Remington made mostly 4-groove barrels through about 5-43. Remington made mostly 2-groove barrels after 5-43.
Smith-Corona made mostly 6-groove barrels through about 2-43. Smith-Corona made mostly 4-groove barrels after 2-43. Smith-Corona made a very few (rare) 2-groove barrels in 11-43.
However, there seems to be many, many exceptions.
The number of grooves was changed to increase production through-put and reduce cost.
