Yep, my first experience of .303's was as an army cadet too. H&S was certainly alien to us. The armoury at our boarding school was at the back of an old Nissan hut, featuring a wooden door and a padlock as security. At one time there was a scare that the IRA were looking to steal rifles in England and as a result, we did patrols in the surrounding woods with the Lee Enfields, each of us having been issued with a handful of blanks!! So the lack of ear protection pales into insignificance, although it would never have occurred to us. I agree, shooting on the MOD ranges with them was all good Boys Own stuff. Especially when we got to have a go on a Bren gun. I remember one time (at band camp - um I mean cadet camp) in South Wales a pheasant found itself half way down the range. Of course, the poor thing got a round apiece from those at the firing point.
The .303 cartridge and a Lee Enfield were indeed thought of as the top bolt action rifle for much of it's service life by many, fairly unsurprisingly. I recently shot a friend's Carcano, a Cavalry Carbine complete with fold-out bayonet and if that's the general quality of other offerings of the period, it certainly explains why the Lee Enfield was so well thought of and maybe even partly explains the Italian involvement in WW2. Carrying one of those things, there's only one way I'd like to go! The bolt action, compared to the Enfield was at best, very poor. I can just imagine Italian soldiers fiddling like hell to get another round up the spout as some Allied troops bared down on you.