Q. I have a classic, 1951-vintage Ithaca Model 37 Featherlight 20-ga. pump-action shotgun with a 2 3/4″ chamber and a 2 3⁄8″-chambered smoothbore Deerslayer barrel for use with slugs. Are there factory 2 3/4″ buckshot loads that have shot sizes larger than No. 3?
A. Please be aware that your Ithaca Model 37’s Deerslayer barrel is made to shoot only Foster-style rifled slugs, not sabot-style slugs. Sabots are made exclusively for use in barrels with cut rifling, not a smooth bore. Of the various smoothbore slug barrels, Ithaca Deerslayers are considered to be one of the very best in terms of accuracy.
Regarding buckshot, there are loads available with pellets larger than No. 3—from smallest to largest these include No. 1, 0 and 00. Of those, the 00 loads are the most prevalent. However, of all the pellet sizes, 00s are the most unreliable as far as pattern density is concerned, so it is best to use them at short ranges only. Because of their downrange characteristics, manufacturers recommend using buckshot only with full-choked barrels.
Read the full article here