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"This unapproved alteration was commonly done by individual soldiers for faster target acquistion"
COMMONLY DONE? It is obvious that the person who wrote this little Gem has never spent time in the WWII or later era when the Lee Enfield was in service.
First of all, there are all kinds of people who were farther up the food chain than the ordinary Infantryman. All of these people looked unkindly to unauthorized alterations to His or Her Majestys property.
Inspections were held on a regular basis, varying in Wartime or Peacetime, but they WERE held. In Wartime, inspections were held when troops came out of the line, who were in rest areas, and before going back into the line. In peacetime, it was usual to have NCOs do an inspection every morning, and possibly an Officer accompanied by the Sergeant Major might on occasion inspect one Platoon or Company. Usually there was at least one major Inspection each week for the whole regiment.
As SMELLIE points out, such people would not really find that the individuals initiative or alteration to Government Property amusing, and anyone who did it would probably find that he would have less money to spend in the near future, and that the RSM and others would take a personal interest in that individual's future education and physical well being. And I will guarantee you that once the RSM knew your name, any unpleasant little task or something that involved digging, lifting, cleaning, or other little chores, your name was the one that came to mind instantly. This individual would also have to contend with the Armourer, who, depending upon how many stuck patches in the bore, or broken pull throughs in the bore that he had to contend with that day, and whose temprement ranged from "Pit Bull" upwards to "Grizzly bear with a sore pecker," could be rather interesting.

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