I'm not sure if this is the right sub but I was wondering about the use of bolt action rifles in both world wars. Especially, in world war 2, why were the militaries of Russia, Britain and Japan still using predominantly bolt action rifles for their infantry? The technology for semi automatic and certainly lever action rifle had been around for a while; and their rate of fire would have been much higher than bolt actions. The benefits of accuracy and range would have been negligible in my opinion. Most of my knowledge on world war 2 small arms comes from video games and movies so maybe I'm off base here, I just got curious while watching the intro to the mummy.
C.J Chivers noted in "The Gun" that one barrier to adoption of new weapons and related technologies like intermediate rifle cartridges pre-WW2 was that there were already huge stocks of the old weapons available. Not to mention the industry to continue production. Keeping the old guns was cheaper, and there wasn't a lot of incentive to pay more for newer gear at the time.
As to lever actions, as I recall the magazines and ammo for those didn't align well with the requirements for rifles in the era. I might be wrong but I think most lever actions used rounded bullets?
There is no real reason to chose lever action over bolt action. Bolt action isn't any slower (watch a good rifleman rapid-fire a British SMLE some time). Here is a previous discussion on bolt vs. lever action.
As /u/Smilin_Dave points out, they had plenty of left-over bolt action rifles. There was concern over the complex gas-operation self-loading mechanism. The British rejected early semi-auto rifles over reliability concerns.