I have recently seen a shotgun which looks new and on the left side of the receiver it has the H&R 1871, mfg in Ilion,NY stampings but in front of the mfg line it has a QR code diagram etched/stamped into the receiver also. Like you may have seen on the Remington R51 or RM380 pistols.
I have never seen this in any NEF or H&R firearm.
Is this rare? or when did this happen.