Caliber conversion on BREN? to 7.92 Mauser or 7.62x51 NATO?

Would like to find out if there were durability concerns when the BREN were converted to fire 7.92 Mauser when Inglis made them for the Chinese Nationalist forces? Was it simply to make the proper barrel and bolt. Would the headspace need to be reset after caliber change, or is it already taken care of by the bolt/barrel change? And were there other structural changes to the rifle? And were any changes permanent changes to the BREN, or could the firearm be changed back to original .303 by swapping out caliber-specific parts?

And then same question regarding the conversion later to 7.62x51 NATO.

Reason I'm asking is I'm thinking if I could have a caliber conversion kit to support my .303 Mk.II BREN, and then I'd be more flexible in ammo choices. Thanks in advance for any insight.

But that it were really that simple to change the calibre ZB.............. It's more difficult than that, believe me. Too complicated to detail here BUT there's a book about the Bren being published by Small Arms Review as we speak (Robert Segal, emmageeman@aol.com) that details in some detail how it was done.

7.62mm NATO............... forget it! That was harder than the 7.92mm conversion. Although there were two methods. The early A1 conversion used very early on by the BRitish and continued by the South Africans that was, er.......... hopeless. Then there was the later A2 type that was superb. But what a palaver to get there - eventually. Both required extensive machining of the body which made it irreversible

Hello:

The 8mm conversion in the USA (permanent) involves fitting the mag well to the ZB26 8mm box mag - making well wider. A .303 bolt with a 7.62 extractor will work with a .303 barrel that has been rebored and rechambered to 8mm.

The 7.62x54r can be done without modifying the mag well - uses the ZB39 magazine fillable to around 20 rounds before issues develope - an additional coil spring is usually required in the front of the magazine to keep the cartridge noses up. Rechamber the .303 barrel (.303 bore is usually ok for decent accuracy) and widen the face of the bolt for the cartridge rim... and you have a second caliber without permanent modification - as long as you have a spare bolt to convert that has good headspace to your converted barrel. I'm not sure if a 7.62x51 extractor is required. Cases fired from this combo take on a new and odd bottle neck shape when fired.

The South African 7.62x51 barrels (DSA has them and the extractors) can be used with a .303 bolt - 7.62 extractor and the ZB39 magazine and this works well enough and is also not a permanent modification.

I have semi auto Brens that fire all of these combinations without material issues - not combat reliability but good for fun shooting.