What stamp is it ? Long Branch

Hi,
Just curious about this. Its located on the Butt stock, not sure if its a service battalion stamp or a personalized thing from previous owner.
Any thoughts ?
Its a LB1943 production and remaining condition is fully match.
thanks

https://www.milsurps.com/images/impo...12380510-1.jpg

Bored soldier or one looking for an easy way to find his rifle in the racks? Can't say more than that, sorry.