It has to be the Lee Enfield, in particular the No4 design.
As a battle rifle, none of the others compare in the speed of operation, in which we are talking over 30 aimed shots a minute. The record is still owned by a Lee Enfield from WW1 that no other bolt action has been able to beat.
The capacity to hold ammo of 10 rounds double that of most other used rifles. I am sorry but thats always an advantage, especially when it didn't see any real increase in the size of the rifle.
Its fixability. It has a removable magazine thats far easier to fix and modify and replace damage. It has replacable bolt heads if the bolt face has been damaged by a ruptured primer or headspace problems and many other features that allow ease of performing field repairs.
The gas bleed system is about as superior to other gas bleeding systems on ruptured primers and so on. It will expel the gas well away from the shooter to the left, rather than on him.
The actual safety is about as good as you can get. It can be adjusted without taking the finger away from a firing position, that your other rifles with a rear bolt safety such as you find on Mauser types, Swiss Scmidt Rubens and Mosins.
Add to that good peep sights, that only the Springfield could compare and in the middle of combat I would argue the Springfield 03a3 sights were overly complex and you didn't have time to do fine adjustments of windage and so on that are nice on target rifles.
It also has a big advantage with variable buttstocks allowing individual fitting to soldier size over 4 or 5 different butt lengths, on a stronger designed butt that is better for smacking someone with than the more delicate Mauser designs with a single built stock.
The No4 Lee Enfield's heavy free floated barrel is a dream for accuracy. The design is far more accurate than its given credit too, even with .303 British, particularly when shooting over 300 yards when it gets better results than even close up. Theres a reason the No4 design was used to build sniper rifles that were in service for over 50 years.
Sure your Mauser rifless like the Kar98, the Springfield and Arisaka are fine rifles but are better at hunting or target shooting than your ww2 combat rifle which is why the Lee Enfield makes it the no1 bolt action of the war.
