The lock bar sight was the standard M1 sight during WW2 and was replaced with the more familiar sight after then. Springfield must have boutht them by the pound for scrap, I've seen many on the M1A.
The "lock bar" on the right side lock the sight from moving after it's zeroed. Sort of. That's the reason it was replaced on every M1 left in service between WW2 and Korea.
You may find someone with a M1 who needs this sight. My DCM M1 Rifle came with a M14 sight, of all things. It went on my M1A to replace the M1 sight.
-- Chuck
The "lock bar" on the right side lock the sight from moving after it's zeroed. Sort of. That's the reason it was replaced on every M1 left in service between WW2 and Korea.
You may find someone with a M1 who needs this sight. My DCM M1 Rifle came with a M14 sight, of all things. It went on my M1A to replace the M1 sight.
-- Chuck