im sorry this has been in my family from my dad up to his dad and we dont know where it went from there and assumed it was from around the ww2 era i will do some research on it
this knife was made for the m1 carbine rifle my grandfather had it on a british 303 so it fits many rifles but it was made for the m1 carbine he was born in 1927 i dont think he went to vietnam because he worked all his life in the space program
The barrel ring on bayonets isn't too different from one to another. I'm just saying that the one in your photo is identical to the one tipping the M-16, even the scabbard is identical. The bayonet for the M-1 Garand is considerably longer, single edged, and has a blood groove down the center of the blade. Do a Google Image search, you'll see what I mean.
i did do a google search you did open my eyes to a few things but i found that it was made for a m-1 carbine rifle not garand and that all rifles are slightly different even if they dont appear to be the carbine m-1 rifle was shorter as was the bayonet that is why this bayonet was made for the m-1 carbine rifle and it fits many rifles not just the ones it was made for because like i said my grandfather had it on a british 303 so........ but it is a very cool bayonet and is from the time of previous wars