short barrelling Bren carbine

[jhard13]

I currently have a Bren carbine, but would like to make it a SBR. I was wondering if anyone could shed light on if the gun will still cycle properly as I am unaware if there are any differences in the gas system between the pistol and carbine.

[AKToday]

Hello jhard13  -  the "gas system" is the same on both carbine, pistol, or SBR -----but the gas port will have to be enlarged more the shorter the barrel, this applies to basically any rifle.  The experts on gas port size will have to chime in on size vs barrel length for the BREN.  You also need to post what barrel length you are wanting to do.

[jhard13]

thanks for your insight. that was my thought I just needed it confirmed, maybe just picking up a pistol to use would be a better option.

[AKToday]

If you are going the SBR route, starting with a pistol would be the best option since it is already set up for the short barrel.   That also assumes an approximately 11" barrel is OK too for what you want.

[promotemma]

I currently have a Bren carbine, but would like to make it a SBR. I was wondering if anyone could shed light on if the gun will still cycle properly as I am unaware if there are any differences in the gas system between the pistol and carbine.

It will be fine.  I wanted to convert my pistol to a carbine and just found a guy on the board who wanted to go sbr and swapped. You might want to just post a trade offer on the classifieds section

[Type5]

I thought about the very thing you suggest, about a barrel swap. I just did not want to mix serial numbers. Nothing wrong with what you did, I am just anal.
Wish CZ would sell the needed parts, I'd would profile the heaviest I could and build my own - could do a 300 Blackout too.

[Manticore_Arms]

I am fairly certain the gas ports are the same size and there are barrel length specific gas adjustment valves. As i recall the gas valve on our in house 16" carbine is marked 5.56 16"

[AKToday]

Thanks for info from Manticore Arms.    I never thought about the gas valve being the adjustment / tuning mechanism for barrel length on the BREN.   Either way, the shorter the barrel, the larger the gas port has to be  "somewhere".

[hawkin]

Message sent jhard13. I'm looking for a carbine and have a pistol..

[promotemma]

I am fairly certain the gas ports are the same size and there are barrel length specific gas adjustment valves. As i recall the gas valve on our in house 16" carbine is marked 5.56 16"

So, if I swapped my pistol barrel with attached piston assembly for a carbine with it's attached valve assembly, everything should be the same otherwise?

thank!

[joe_sun]

Just wanted to share some info.

On the CZ USA 805 Bren group on Facebook we measured the gas port holes and this is what we came up with

Pistol S1    1.60mm and 1.30mm
Carbine S1 1.40mm and 1.10mm

It seems as if just changing the regulator after a barrel chop will set the gas system correctly also if a pistol is over gassed from shooting suppressed a carbine regulator might help out. Also the adverse setting on the Carbine is so bleep close to the standard pistol setting it might be possible to just set it at adverse and then you MIGHT have the added benefit of having a "suppressor" mode.