LOTOW pg44 - A cavalry sabre is listed as a hand weapon.
LOTOW Alamo pg 39 - rules differ from posse based game vs massed battles
Posse - see above
Massed - Fighters w/ Swordsman skill can re-roll 1's when rolling to hit enemy in combat.
Although classed as a hand weapon, if your cavalry did not have hand weapons (sabres), any Hand to Hand combat would be classed as unarmed which has -1 modifiers on who wins AND rolling to wound.
I could not find any other references in LOTOW, Alamo, Frontier or Showdown...
Hope that helps.