Just some random advice, but advertised barrel length is not always what the real barrel length is. Even here in the USA. There was a great thread on it at M4Carbine.net a few years ago.
I have no knowledge of the 14" Bren 2 barrel, but I would recommend you get a thin rod and lower it down through the barrel with no muzzle device attached until it rests on the closed bolt face. This is how the ATF measures barrels and in other countries sometimes they use different methods, on top of just rounding numbers.
Better to be sure, than be Bubba's boyfriend.