Old Name, New Gun: The CZ 805 Bren Modular Rifle

Old Name, New Gun: The CZ 805 Bren Modular Rifle


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.  The sides have (each) two cooling slots and three barrel screws openings, as well as a cocking slot with rounded cocking handle inserting opening.  The cocking handle can be inserted from either side, without any adverse effects on operation.  The barrel screws also hold the side rails, and their openings are filled with polymer sleeves to eliminate vibration and hinder heat transfer.  The ejection opening is on the right side of the upper receiver. From the rear it is closed by a back plate, from the front by the barrel assembly, and from the bottom half by the lower rail, being the part of the barrel assembly, and the other half by the lower receiver. The interesting point here is, that the lower hinges not on the upper receiver, but on the rear end of the bottom rail.

The Barrel Assembly
The barrel assembly is exchangeable as a whole unit, and resembles the one used in SCAR – at least in the mode of fixing – very closely.  The locking ferrule is screwed onto the rear end of the barrel.  The rear two pairs of the barrel fixing screws are screwed into this ferrule from the sides.  On top of the ferrule there is a piston guide, directing it on the way to hit the bolt-carrier. On the bottom another two screws fix the lower rail to the ferrule. At approx. 2/3 length of the barrel the gas port is drilled, covered with gas block.  Just aft of the gas block there is a U-shaped former, into which the bottom of the forward bottom rail screw is screwed, and into which sides fit the forward barrel fixing screws pair.  The locking ferrule and this former keep the barrel free-floating as much as possible in a gas-operated gun.  The muzzle is threaded for a countering nut and muzzle devices – standard bid-cage flash hider/compensator, a blank-firing-attachment or a sound moderator. To exchange the barrel one has first to field-strip the rifle (the bolt head has to be withdrawn from the locking ferrule of the barrel, and lower receiver has to be detached from the bottom rail), then to unscrew six barrel fixing screws and withdraw the barrel.  It can be done in field conditions, but it is by no means a quick-change barrel.  Anyway, it takes a torque wrench to reassemble it in a rigidly-regulated sequence.  Whoever changed a barrel on SCAR, knows the drill.

The A1 and A2 barrels are identical save for the length and theoretically they can be exchanged freely – but in reality the Army ordered the rifles in final configuration with no spare barrels.  It is then a modular system, but not an operator-configurable one. The bore is 6 grooves, one right hand twist in 7 inches.

The IDET 2009 fair saw the premiere of the CZ S 805 A1 rifle with 40mm G 805 grenade launcher, still in smooth prototype form of the opening slide. The rifle still has an old stock, but already features a new upper receiver. Note the early rendition of the ZD-Dot and DV-Mag 3 magnifier, still mounted with Allen screws. (Andrzej Kinski)

Lower Receiver
The lower receiver is divided into two parts: trigger mechanism housing with pistol grip and the exchangeable magazine well.  Both are made of polymer, connected by a T-rail and corresponding slot, and pinned.  The pin can be started out by bullet point, and then pushed out with a firing pin.  After the pin is out, both parts can be slid one from another and separated.  In both 5.56mm magazine wells the magazine release is fully ambidextrous – by bottom lever in CZ proprietary magazine, and by buttons positioned on both sides of the STANAG-magazine well.  The bolt hold open is positioned inside the magazine well and provided with ambidextrous push-buttons.  Caution: these can only activate the hold-open when there’s no magazine.  The release is ALWAYS by pulling on the cocking lever.  This is a drawback, but Czech soldiers used the same system on their Sa-58s for half a century, and 50 years of tradition is an undisputable power in each Army.  The standard magazine well is the CZ plastic magazine one, but STANAG-magazine wells are going to be provided for the Special Forces to insure interoperability and also for the future A3 LSW variant, to enable the use of the Beta C-Mag and other high capacity magazines fitting the AR-15 magazine well.

The complete lower is a swing-out affair, fixed by two cross-pins.  After the cross-pins are withdrawn, there are corresponding sockets in the stock where these can be stored.  Nothing new for any HK user.

The modified (M2011) pistol grip has exchangeable backstraps, also secured with a pin.  Two sizes are available, standard (M) which fits most hands, and XL.

The trigger mechanism is a modified AK with a burst limiter – not much changed since the Lada, except perhaps for the flat trigger/selector retaining spring, which is another of the Sa-58 left-overs.  The selector has four settings, 0-1-2-30, all within a right angle, which means that separations are diminutive, just 22.5 degrees.  Pictograms are dots in two colors: white dot means SAFE, and then there are red dot(s), for single, burst and continuous fire.  The lever is well within reach and moves up to SAFE, down to FIRE, just like the 1911.  A possible civilian-legal variant would perhaps only have two settings, SAFE and FIRE also in a 90 degrees arc, which would be best for it.  The burst setting is pointless, with the two-rounds burst – fortunately it resets itself after releasing the trigger prematurely, unlike the M4.

CZ 805 A bolt carrier with bolt, cocking handle out. The rear part shows the automatic firing pin safety. (David Pazdera)

Pros and Cons
This author had the opportunity to check out the CZ 805 Bren at a shooting range, and the occasion, however brief, left me with several remarks to make.  A 4.2 kg heavy rifle has no right to display a noticeable recoil or muzzle flip with the 5.56x45mm round, and this truth was once again proven by the CZ rifle.  It takes a long burst on fully automatic to swing the muzzle noticeably, although still keeping a full magazine-dump within a torso target at 15 meters was easy – as opposed to the Sa-58.  The shoulder stock is made of plastic, and by contrast seems to be weightless at all, which means the rifle is heavy on the nose.  That’s not bad for dynamic sweeps, but if you keep it ready for a long spell of time, your weak hand would finally become sore.  And definitely make use of the 6 o’clock rail by attaching a foregrip.  If you don’t, you have to watch your supporting hand thumb position – if you utilize the cocking handle on the left side of the gun and you’re not a southpaw, that is.  Again, whoever shot the SCAR, knows why – the cocking handle is reciprocating, and with bolt in battery it is very easy to place your thumb in the way, if you support the gun by magazine well.  Been there, done that – you better don’t.  The cocking handle stripped the half of my thumbnail in no time. Nothing you’d like to repeat, believe me, although not incapacitating.  The rifle is mostly flat, but has rails all over – waiting to skin your fingers alive if you don’t muzzle them with rubber covers or wear gloves, or preferably both.  All controls are within easy reach (or at least – within MY easy reach) and work quite nicely – rotate easily, but firmly keep their positions, or spring back energetically after release of the push buttons.  The only drawback in that area is the safety-selector lever, with four settings within 90 degrees – that’s way too cramped.  The plastic magazines are said to be interchangeable with HK G36, but fortunately omit the integral coupling devices, sticking out from their sides.  Anyway, they’re still wide and big – it’s hard to believe they only keep tiny 5.56mm rounds.

The long 40-centimeter overhead monolithic rail has enough room for any combinations of sights one is likely to haul.  The factory sights suite consists of a set of CZ’s own BUIS and a Meopta ZD-Dot red point sight.  Whoever used any variation of the M68 CCO would be at home with the ZD-Dot, housed in as big a tube with as many protuberances as most of the M-series Aimpoints, and utilizing the same time-proven red dot reticle.  By the way, it’s the Meopta who makes most of the Aimpoint lenses.  Each A1 rifle and A2 carbine was ordered with a ZD-Dot.  1,386 would get an ‘enhanced optoelectronic suite’ consisting of two 3x magnifiers, one day-time, one coupled with NV device and a DBAL-A2 laser module.  The magnifiers, at least the daylight model, DV-Mag3, gives a very sharp, even image.  The optics are really good – but Meopta still has a thing or two to learn in tactical optics.  No quick release means – so while FIBUA you have to undo a lever and take the magnifier out, unlike the Aimpoint QD pivot mount.  But the prototypes had both red point and the magnifier mounted with Allen screws, so that’s an improvement over the previous version, nevertheless.

Que Sera Sera
The future of the CZ 805 is still ‘not ours to see.’  It has just begun it’s travel, and the soldiers would no doubt find many ways to give the CZUB team a reason for headaches.  For some reason or other the modular rifle have in reality became a fixed configuration one – perhaps the user had not matured yet to have too many choices left.  The plans are still ambitious, though, and in May 2011 the existence of the new A3 was announced – but in a little strange way.  The A3 ‘soon in a theatre near you’ is a bipod-fitted LSW/DMR – that’s more or less consistent with the program.  But then the CZUB announced it would be a 7.62x51mm weapon, which then should be a B3 rather, and the first version of the long-awaited B full-power round configuration.  The civilian-legal semiautomatic variant of the A1 has also been hinted to, so perhaps there would also be a U.S.-market version with a 16-inch barrel – which would certainly be greeted with much interest.