An answer from CZ-USA about the differences in the BREN 2 pistols imported

[armoredman]

Some discussion has happened here and elsewhere about the differences in the S and MS pistols brought in so far. I reached out to CZ and this was the reply, shared here.

The S models don’t have a “standard” configuration (not a cataloged item), the barrel might be configured 14x1 with and without bayonet lugs, as well as ½ x 28 barrels and 5/8 x 24, neither of which will accept bayonet lugs)

 

The 7.62 x 39 Ms models should be coming with 5/8 x 24 threads and no bayonet lug. The first shipments had 1/2 x28 threads.

 

The firing pin spring is included on all 5.56 models.

No firing pin spring was included on the full auto 7.62 x39 guns to prevent light strikes, I’m not sure, but if I had to guess, it is likely the S models in 7.62x39 were sold without a firing pin spring like the select fire guns, but they then added the springs back in on the MS guns.

 

The extractor cut outs were something only needed on the 7.62 x 39. (the extractor extends past the bolt head on the 7.62 x 39 extractor necessitating the additional clearance, whereas the 5.56 extractor has always been below flush.)

Hope that clears up a few things, if anyone was curious.

[Brenfan]

Please excuse my ignorance, but what is the difference between s and ms?

[armoredman]

The S model is the mysterious 300 pistols imported before the official BREN 2 MS pistol was brought in, with a wild variety of barrel lengths in both 5.56mm and 7.62mm. They had the military spec forearm, not the one for the US market. Well, 298 now, apparently 2 have already been destroyed, from one report I read, no idea how.

[wags68]

2 have been destroyed?! Wow, what a shame.  Any link to the report by chance?

[armoredman]

I don't think it was by ATFE or anything like that, but mischance and the "dumbs"...

[Manticore_Arms]

The S model is the mysterious 300 pistols imported before the official BREN 2 MS pistol was brought in, with a wild variety of barrel lengths in both 5.56mm and 7.62mm. They had the military spec forearm, not the one for the US market. Well, 298 now, apparently 2 have already been destroyed, from one report I read, no idea how.

What report, and when you say "destroyed" does that mean "blew up" or "chopped into parts by a local PD or the ATF for illegal ownership" or something similar.

[sneakyhenry]

I have a Bren 2s and it's aesthetically very different to the Bren 2Ms.
1. The upper is a monolithic rail section with 2 MLOK slots at the 3, 6 and 9 O'clock positions. It's not a 2 piece upper like the Bren 2 Ms (M stands for Modular hand-guard as you can clearly see near the gas regulator)
2. The monolithic upper receiver has a lighting cut in it.
3. Both sides of the Bren 2s receiver (the upper is the receiver in the case of the Bren 2) have been milled out where the serial number is located on the gun, where the Bren 2s nomenclature is located on the gun and where the "made in Czech Republic" is located on the gun. Look where the AR-15 like bolt release paddle is located on the left side of the Bren 2s pistol and you'll notice a big chunk of the upper milled out about a 1/32" deep (these are very noticeable if you check out current videos like mishaco's videos).
4. There are two different style magazines for the 7.62x39 Bren 2's there is a civilian translucent magazine and a all black military magazine with a window at the bottom and steel inserts on the lips. Mine came with the military style black mags. However, both are now imported into the country. The Bren 2s military versions came with regular GI Stanag magazines and the Bren 2Ms comes with a CZ magazine that has 5.56 & 300 BLK nomenclature on it (which is pretty cool).
5. The 12 0'Clock picatinny rails are slightly different geometry and the Bren 2s' picatinny rail numbers go in the opposite direction then the Bren Ms's do. (the Bren 2s' first picatinny rail behind the rear site is numbered 34 and the Bren 2Ms' first picatinny rail by the behind the rear site is 2).
6. The early 300 models of the Bren 2s in 7.62x39 have a thread pitch of 1/2x28 UNC, while the new Bren 2Ms in 7.62x39, have a thread pitch of 5/8x24 UNC.
7. My Bren 2s in 7.62x39 doesn't have a firing pin spring.


There might be more differences but these are the ones that are easily recognized. I'm sure glad I got 1 of 300 military versions that were imported last year. However, I do find the Bren 2Ms pretty aesthetically appealing as well and it will have a much bigger base for spare parts and accessories.

[armoredman]

The S model is the mysterious 300 pistols imported before the official BREN 2 MS pistol was brought in, with a wild variety of barrel lengths in both 5.56mm and 7.62mm. They had the military spec forearm, not the one for the US market. Well, 298 now, apparently 2 have already been destroyed, from one report I read, no idea how.

What report, and when you say "destroyed" does that mean "blew up" or "chopped into parts by a local PD or the ATF for illegal ownership" or something similar.

I wasn't given many details, but mostly what I hear is the "blown up" style...

[sneakyhenry]

I wasn't given many details, but mostly what I hear is the "blown up" style...

Armoredman,

When you say "blown up" are you meaning somebody was shooting these two Bren 2s' and they blew up while being fired? This doesn't make any sense because they are same internally as the Bren 2Ms. I guess I'm just confused.

[Aries144]

If you have a bad kaboom, it can deform or tear an aluminum receiver. That's a lot of pressure entering the receiver. I'm guessing that's what happened.

[armoredman]

I would hazard a guess, since there was no public outcry, that it was operator stupidity. I also cannot confirm that that WAS the issue, for all we know they could have been confiscated or stolen, very little hard detail.

[sneakyhenry]

It can be kinda scary shooting my Bren 2s (9” 7.62x39) because of the fireballs you see when a spent shell is getting ejected and you can see some kind of flame spark in the piston system through the lighting cut in the upper receiver. I have shot about 300 rounds with no issues so I guess it’s fine, I’ve just never seen that with any other self loading rifle.

[Magsz]

Question.  I cant get a solid answer on this from anyone.

Are all of the 14 inch barrels on the MS guns equipped with a bayonet lug?  If so...ew....

[Aries144]

The best answer for now is looking at unique pictures on gunbroker. (Where the seller is taking pictures of his actual example.)

The pictures are showing all 14" 5.56 Bren2MS DO have bayonet lugs, while all 14" 7.62x39 Bren2MS DO NOT have bayonet lugs.

All 50 14" Bren 2S in 7.62x39 DO have bayonet lugs.

No Bren 2 models other than the 14" have ever had bayonet lugs.