to me is the only sight to go to for info on these fine rifles.
M38's do not have bayonetts & never had any ability to mount one which is why the M44's were developed.
M91's are the oldest & longest ones being made from early 1890's till the early 1930's with about 50" + total length.
M91/30's & the Finnish M39's can be had with round or hex recievers & were in production till well after WWII & the along with the Cossack & Dragoon rifles they are around 48" long.
All carbine models for the most part are around 40" in length.