My Father was in the Irish Army during the 1950's; he loved shooting the Bren on the 600 yard range at the Curragh.
I had wondered about that scene; where the sniper swaps the T for the Bren. I thought it was a "movie moment" . It's good to hear that it's actually part of the history.

I was pleased to have the opportunity to shoot a Bren earlier this year; although it had been reduced to single shot function. (manually operate the bolt to load from the magazine)