I had the same experience as above with that Pakistani ammo, a mix of outright duds and dangerously long hangfires. Add to that the corrosive berdan priming and they are at best donor bullets.
The actual British surplus is also corrosive but usually reliable.
The best of the military surplus is the Greek HXP. Boxer primed in brass that holds up pretty well (for a .303), and accurate.
Interesting side note, since the Russian x54 round uses the same bullet diameter and is a just slightly larger round with the same pressure, some folks have just used a chamber reamer and blown their .303 British rifle out to the Russian. Of course, that was when you could get the Russian ammo...
I don't know about the legality of FMJ where the OP is, but interestingly the British used a wood filler in the front of the jacket to make the bullet back-heavy. This tended to help long-range accuracy but I've read it also made the bullet tend to tumble on impact which would reduce the risk of pass-through.