Question seems a little vague in that penicillin has prbably saved more lives, certainly more than a Lee-Enfield.
I can only guess that due to its accuracy the rifle greatly reduced the need for close quarter, hand-to-hand fighting in that enemy combatants could be engaged and negated at greater distances.
Thanks philtaz, I initially thought that too vis-a-vis the battle of Mons in 1914 early in WW1 when thw British stopped a numerically superior German army with sustained accurate rifle fire