JerryB08

History seems to have answered your question.

During WW2, the Britishicon had stocks of both rifles but chose the No4 for Sniper conversion.

Post WW2 as the sport of Target Rifle shooting continued to develop, in countries where both rifles were available, the No4 was the main rifle chosen.

Having said that, any rifle that groups can be deadly accurate in the right set of hands, be it a No1 or a No4

Paul