The very first high powered rifle I ever fired was that darn No. V Jungle Carbine and knocked me all over the place. The .303 Brit is a serious rifle!
I believe that the Mauser action is considerably smoother and more controllable in rapid fire - but I wouldn’t be able to challenge Sergeant Instructor Snoxall with anything less than my trusty M14!
The one thing that I’m sure of, is that the Enfield rifle in .303 would drop any man on Earth with one shot. Surviving five shots is unthinkable.
They cut down the weight of the rifle significantly by reducing the stock, eliminating most of the fore-end, and shortening the barrel, without reducing the muzzle energy of the round. Bad idea!
I loaded lighter bullets (150s i.o. 180s or 174s) with a reduced powder charge, and that helped some. But not much. An unpleasant rifle to shoot.
Same thing happened with the Walther PPK - which is a nice shooting gun in .32 auto, but .380 kicks like a doggone mule. I had a nice pre-68 one, but I sold it because I didn't like spraining my wrist. The modern compact .380s are designed for the round and are a pleasure to shoot.