The US airborne units carried a bunch of M-1 Carbines, because they expected to be cut off from supply, and the lighter M-1 Carbine and lighter ammunition let them carry more ammunition. Carried a bunch of M-1 Garands too.
M-1903 Springfield: 16 rounds to the pound
M-1 Garand: 19 rounds to the pound
M-14 Garand: 20 rounds to the pound
M-1 Carbine: 30 rounds to the pound
M-16: 40 rounds to the pound
I saw a supposedly genuine folding stock for a M1 carbine on eBay the other day, went for $208.00, I would like to have one, but not that bad.
M-1 Garand: 19 rounds to the pound
Might want to check that. Both shot the same ammo, but the Garand ammo was packed eight to an en bloc clip, which added weight. The Springfield had a stripper clip at most.