Feed problems with the last couple of rounds are inevitably the magazine spring. It cannot be anything else, because the other have all fed successfully in any case!

When the magazine spring is at full stretch, ie, at the top of its travel, it is, by definition, at its weakest. And if the temper has slightly failed, then it simply won't overcome the problems/obstacles, friction being one....., that it encounters.

You can stretch it, twiddle about with it, bend it shape it and anything else you want with it, but short of hardening and tempering it, its fu......er...., knackered.

This was one of the very first lessons during your basic armouring phase. Duff magazine springs were even inserted into the magazines during our live firing practices by the affable Major Viney as he taught us the basics of ballistics.

Magazine springs and rivets were available as spare parts as I remember