i'll wager on LD's side
every lee enfield ever made had to pass a firing test , from a vice like mount it had to hit a 4" group within the sights adjustment range and then do so at 600 yards witha 8" max allowed
more than that it was tossed
Springfield's i have the ordinance master manual if you'd like a copy and can read about it
they had a indoor set up but just as accurate
fail to meet tests sent the rifle back to be rebarreled
i know they did so with the M14 too and i think that was the last US rifle ( main rifle SF and sniper stuff excempted ) to get a proof fire , but dont quote me on that part , but i remember a stink about the M-16s not being proof fired but came factory pretty good
this is a Firing Proof its about 1/2" in Dia.