To thread a British Bren rifle barrel onto an enfield no 4 mk 2 receiver and have it shoot and function properly?

Technically yes, although it would be a ton of work.
As the Bren uses an interrupted thread, as well as lacking the same extractor cut as a SMLE, you would need to cut the barrel back, cut new threads to match the SMLE receiver, as well as an extractor grove, and then recut the chamber.
After that, your only issue is the Bren barrel having a gas port, which would need to be capped in some way (pin and weld it shut, make a false gas block, etc) although the spot would still result in uneven wear in the barrel due to collected fouling.

So while it could be done, you'd burn up a bunch of time and ruin a good Bren barrel. Personally if you want a heavy barrel, I'd just buy a .303 barrel blank and cut the threads and chamber in it, which would give you something similar to the Mann accuracy device.

The Enfield receiver has regular barrel threads, a bren barrel uses a set of interrupted threads.

You'd have to mill the barrel and thread it, then set headspace. If even possible.


The UK59 doesn't use interrupted threads, but people have modified them to use on mosin receivers.


Sorry to point this out and not trying to sound like a dick, but this should have been clearly obvious without posting the question here.

Well you do sound like a dick, I'm not a gunsmith and thought this would be the place to ask a question. If it was clearly obvious to me I wouldn't have asked the question. Sorry I don't have your level of knowledge or expertise.

It is what it is. Simple machine shop knowledge, nothing special.

You don't have to be a gunsmith to figure out that interrupted threads will not thread into normal receiver threads.