Lastly, the middle finger is used to pull the trigger.

Not as clear as I'd like, but here it is.

Notice that the thumb and first finger stay on the bolt and the middle finger pulls the trigger.

This was so fast, that I was able to fire about 1 round per second with little practice.

This was the rate of fire that the British wanted to get.

The first time they used this tactic against charging German troops in WWI, the Germans reported to their Officers that the British had automatic weapons.

As we walked to another range for some more pics, I was carrying the rifle as many, many Brits had carried them across the plains of Africa, on the shoulder, muzzle forward.

Here I am working the rifle, volley fire.

On the shoulder, brass in the air.

And finger on the trigger, ready to fire.

Conclusions:
It is amazing how quickly the rifle can be fired in this manner.

SMLEs are great pieces of history.

You can often find them for very reasonable prices at gun shows, don't miss a chance to get one and enjoy it.