Kurfürst
Staff Sergeant
The British because the Lee Enfield was a better rifle. With a faster rate of fire and double the ammunition it had clear advantages.
The SMLE didn`t have a faster rate of fire. It may have been more suitable for fast firing than the old WW1 Mauser with its straight bolt handle (which OTOH was ballistically superior), the Kar98 which had a similiar bent bolt handle. Practical rate of fire was the same.
As to double the ammuniton, I fail to see the point. The SMLE magazine holds 10 rounds, but it was fed by the same 5-round clips as the Mauser, Mosin, Springfield etc. I don`t see much difference between inserting two five-round clips and then firing 10 shots, or firing 5 shots, insert a five-round clip, fire 5 shots again, insert another five-round clip. In practical terms, the second clip is probably much more difficult to insert into the SMLE, given you already have rounds in the magazine. More than five rounds in these clip fed bolt action rifles do not seem to have gained any popularity with designers and soldiers - for the WW1 Mauser Gewehr 98, the Germans introduced a 20-round magazine, but it was abandoned.
Infantry soldier carried apprx. the same number of rifle rounds with them, ie. 45 to 60.
As to the merits of the two design, IMHO the extreme success of the Mauser 98 based bolt action rifle systems speaks for itself. As I said, it was the AK of its time. No country that had any say in it choose the SMLE over it, the latter is pretty much restricted to the British Empire and its former colonies/dominions. Even the British wanted it before WW1 over the SMLE, leading to their Pattern 13 rifles with the Mauser bolt.
As to using enemy weapons, ammo is a big consideration. British troops could pick up an MP 40 and use it without problem, their Sten fired the same 9mm Parabellum round; the bolt action rifles OTOH fired completely different rounds.