long branch sniper ?

[Maple_Leaf_Eh]

... The "71L" is engraved whereas the "0350" is stamped...never have seen this done on a Long Branch sniper.serial number always stamped.
....

There is mention in the literature that Long Branch had great difficulty drilling and tapping finished recievers. The solution was to assign a block of build block for rifles to be converted. (I don't know quite how they would select rifles for accuracy when they weren't finished.) Once converted, someone would individually apply the serial number.