Bren guns, anyone?

[rob love]

Originally posted by Steve Guthrie
I notice each of the guns in the row on the floor has a spare barrel placed beside it.

When these guns were issued, was a spare included?

If so, was it always kept as a 'spare' or were the two barrels rotated ?

The barrels were also serialised to match the Bren. The barrels were headspaced to the gun, and this prevented the barrels from being mixed up during "cleaning parties".
It is not uncommon to find 3 or 4 serial numbers on barrels, with the earlier ones barred or XXX'd out.
This procedure is still used today with may of the quick change barrel MGs in Cdn service, including the newest version of the .50 cal.