Gas regualator hole sizes ?

[tr63]

Anyone know if the holes sizes in the gas regular for MkI Bren gun are the same dia. as the holes for the Mk III Bren Gun ?

[Brit plumber]

I can see no reason for them being different, as far as I’m aware the only difference is the overall thickness/width of them. The Mk3 is narrower to match the narrower housing.

Rather than confuse matters by using the correct nomenclature for regulators and barrels, I’ll stick to gun marks.

If you fit a Mk1 gun reg to a Mk3 gun barrel, the reg appears to wife, fit a Mk3 gun reg to a Mk1 gun barrel and it is too narrow and looks odd but they will function fine regardless.