The S805 Pistol Is Here; MAC Takes A Look

Nathaniel F
by Nathaniel F

The S805 Bren pistol from CZ, the company’s next-generation modular follow-on to the often-mistaken-for-an-AK Vz. 58 has finally reached American storefronts. We’ll talk about the rifle itself in a minute, but first Tim of the Military Arms Channel has already released a medium-length video discussing the new pistol, embedded below:

Tim mentions that the S805 and SCAR seem to be “siblings” sharing many similarities. This assessment is right on the mark, since both rifles trace their parentage to the German G36 rifle. Tim further raises the question of which weapon might have come first, a question we can answer here. The SCAR solicitation (originally called “SCR”) began in early 2003, with the first FN SCAR prototype submitted in June of 2004. According to Leszek Erenfeicht writing for SADJ in 2012, the development of the 805 Bren began in 2005, after several abortive attempts to sell the AK-derived Lada/CZ2000. Judging by these dates, the FN SCAR began its development first, but it’s unlikely that at that point CZ had enough information to substantially copy any features from the Belgian design. Indeed, the case for the S805’s parentage being overwhelmingly German is made stronger by another section of the SADJ article:

The upper receiver is monolithic, with a full length Mil-Std 1913 rail running on top. The upper is machined out of a forged aircraft-grade aluminum billet, has a form of an inverted U-sectioned through, completely open at three sides. Initially it was planned to be made of polymer plastic, but during the development an aluminum ‘interim’ receiver was used, and so it remained.

This explains much about the S805’s chunky upper receiver. The profile is much heavier than it needs to be given the material – which is exactly what one would expect given the original intent to make the upper receivers out of polymer. The contours of the receiver likewise are strange for a milled piece, but make perfect sense if one imagines them injection molded from fiber-reinforced polyamide, instead.

The similarities between the S805 bolt carrier in this image and the G36 and HK243 bolt carriers below are striking. The bolt configuration appears to be a direct copy, while the carrier has a different charging handle design (closer to the SCAR), but also copies the firing pin safety of the HK243. Also visible in this image is the soft contouring of the receiver - contouring which adds machine work, but would have been of no consequence on the original injection molded polymer receiver design. Image source:
Image source:
Image source:

The 805’s gas piston, too, more closely resembles the Rottweil maker’s rifle than it does the Herstal gun:

The S805 piston in this image is not identical to the G36 pistons below, but more closely resembles the German design's short-stroke operating rod than it does the SCAR's small tappet gas piston. Image source:
Image source:

Finally, CZ added an extra step, but otherwise disassembly is very similar to that of a G36:

At SHOT 2012, I got my first look at the Bren rifle… And I wasn’t as impressed as I expected. Mechanically, the gun was unremarkable, and it was quite heavy and chunky compared to the competition. The thing that left the greatest impression on me, however, was how every member of my four-man group drew blood attempting to field-strip the rifle. The cross-pins holding the rifle together featured detent clips that were not deburred. When one pushed on the pins, the detents were compressed and pinched the finger of the poor chap trying to get the rifle open, hard enough to draw blood. Despite being warned of this by myself (the first of the group to disassemble the rifle), each member in turn managed to bloody himself trying his hand at the procedure. The only solution, we found, was to push on the pin with the tip of a fingernail.

However, the video above seems to show that the pin detents have been modified. Where previously, the pins could be pushed through (as long as the blood sacrifice were made), Tim indicates that the new pins have to have their detents manually compressed before they are pushed through, removing the necessity of the aforementioned ritual.

Tim mentions that the bolt cannot be separated from the bolt carrier. This feature is in my opinion a very bad move on the part of CZ. In the Louisiana humidity, I have had bolt carriers and bolts rust together as the rifle sat in storage, making unlocking and locking very difficult. The solution is to separate, clean, oil, and reassemble the operating group – a maintenance procedure that is not possible on the Bren.

The S805 Bren is a heavier gun than it needs to be, but otherwise seems like a reasonable rifle… Provided the user does not need to separate the bolt and carrier.

Nathaniel F
Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. He can be reached via email at

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  • Alex Pei Alex Pei on Aug 04, 2015

    That's disappointing. For what these things cost, I would have not have expected issues with the weight and bolt disassembly. I was planning on getting one of these, guess I'll pass.

  • Bob Bob on Aug 24, 2015

    Maybe they think your just going to pour lube into the bolt/bcg area and rack it a few times to prevent rust and move what gunk is in there out? I would think with the weather there they wouldn't of put a huge design flaw that we would think it be in the gun.