The SLR was invented solely so that NCOs could inflict "pokey drill" on squaddies if there was any spare time.
https://secure.flickr.com/photos/164...07/6841172936/
Oh the sheer fun
of holding 11 pounds of rifle out at full extent, with the first to drop before the NCO called the change getting a good shouting at.
(Actually I seem to recollect it more in the first few weeks of joining,
perhaps they used it as a screening method to see who would stick things out or not. )