Need advice on .303

I just bought a old enfield mkIII.I planned on putting a Leupold scout scope on it and use it for deer and hog hunting.The problem is I bought it and never really paid attention to how it had been spoterized by the previous owner.I noticed the charger bridge had been removed but a guy I was showing the gun to pointed out that the sight had been dovetailed into the barrel and he thought it would be dangerous to shoot.I've shot it and nothing happened but I haven't shot it since noticing the sight.You guys have messed with enfields more than I have what do you guys think.It's dovetailed kind of like an .22 rifle sight would be.If it's safe to shoot i'm going to put on a ashley scope mount and leupold 2.5x scout scope.

I don't have any way of getting pics but what I was worried about is the small dovetail cut into the barrel for the sight.It's about the same size cut in the barrel as most of the old single shot .22s have.I was just wondering if the barrels are thick enough to handle the pressure of the round going off.I've shot it before without a problem so I'm not terribly worried,but thought I'd ask you guys here just to be on the safe side.