What Is Cz 805 Bren (Review) – Any Reported Problems With It? And How To Fix?

This post may contain affiliate links. When you buy through links on our site, we may earn an affiliate commission (no added cost for you).

Bren 805 was specially designed for the sake of the Czech Republic service rifle before being commercial for several years. The most well-known version is the CZ 805 S1.

Though it is now no longer available for open sale except for law enforcement special orders, you may still manage to own a CZ 805 Z1 in one way or another.

That time, several questions are coming across your mind:

  • Is CZ 805 S1 worth your investment?
  • Are there any reported problems with it? - If yes, how to fix?

Keep reading as we give you the complete answers here.

An Overview of CZ 850 Bren S1

The CZ 805 S1 is a gas-operated rifle, which draws quickly thanks to a user-adjustable gas regulator and the short-stroke 5.56 NATO chambering. The reversible charging handle makes this rifle ideal for the ambidextrous shooters.


Source image

Type of firearm

Piston-driven rifle


Semi-automatic civilian variant; self-defense; target practice; or hunting.

Type of magazine

AR15/M16 (STANAG magazine)


.223/5.56×45 (5.56 NATO)


Aluminum frame; Polymer grips; Cold hammer forged, muzzle threaded 1/2x28 barrel


Barrel length: 16.2’’; Overall length: 39.’’


8.43 lbs


Flip-up adjustable iron sights; 2 rear aperture sizes


Ambidextrous thumb

Specifications of CZ 805 Bren S1 Carbine (Source: CZ-USA.com)

An Insight into Features of CZ 805 Bren S1

Structure and Design

All components together give off a solid and tight feeling, yet the rifle is lightweight - it is what you can expect from such a high-quality weapon.

There are two Picatinny accessory rails attached to the aluminum upper receiver: one running from the handguard front to the rear and another running from the magazine front to the handguard front.

The rear has two flip-up iron sights with aperture whereas the magazines are made of two 15/M16 pattern metal ones.

The barrel is 16.2’’ in length and lightweight enough with a muzzle brake to accelerate the follow-up shots.

All-black look and lightweight in hands

Source image

The adjustable gas block is another thumb up!

When it comes to CZ 805 Bren S1, there are two settings for the gas block to feature gas ports at the rifle frontend and to release excess gas. Even more, the gas system is removable for cleaning and maintenance at ease.

Such the adjustable block not only reduces recoil, wear, and tear but it also allows the rifle to run cleaner and more reliably.

Modular Ambidextrous Rifle

Interesting enough, Cz 805 Bren S1 is both right and left-hand friendly. The charging handle possibly swaps either side according to the preference of the shooters.

The safety selector and magazine latch are bilateral as well. There are even colored marking positions to help you adjust the safety selector securely.

Both magazine release and selector switch are ambidextrous

Source image

Though the manufacturer initially sets the cheekpiece for the righties, you can reverse it for the left hand and accommodate the cheekpiece to the eye-to-optic position since the side-folding stock supports four different positions.

Gas-piston Action

CZ 805 Bren S1 is a short-stroke gas piston rifle. This kind of operating system is the common basis for many modern semi-automatic rifles.

The short-stroke gas piston reduces felt recoiling parts. Accordingly, the piston moves separately from the bolt group to impart the energy in abrupt push so that the bolt carrier continues through the kinetic energy.

Shooters, in turn, feel better control of the rifle since they do not have to stop at the end of the bolt carrier travel.

With CZ 805 Bren S1, there are two settings for gas-piston operation: one for normal operation and another for adverse conditions in which the rifle is dirty and requires more gas to operate the action.


The reach of Cz 805 Bren S1 might be a bit longer for those having small-size to medium-size hands. As a result, they find it hard to touch the controls without adjusting their grip.

Fortunately, this rifle supports a polymer buttstock that is adjustable in length.

On being off the bench, the gun comes to your shoulder easily with an excellent balance. The trigger is lighter than 5 pounds once a take-up shot. The two AR-15 style magazines make faster reloads as well.

Overall, the action of the S1 version is smooth like butter thanks to the short-stroke piston, excellent heft and multi-port muzzle brake.

Reported Problems with CZ 805 Bren S1

CZ 805 Bren S1 is such a good-all-around gun that malfunctions hardly occurs.

There are only several possible issues as follows:


Possible Reasons


The bolt hold open gives off the feeling of an afterthought.

And, the bolt handle is unable to catch from the left-hand position.

There is no “both release” button.

You have to transition your shoulder, smack the charging handle, and do the reloading.

Non-locked bolt or non-fed cartridge.

The magazine has been damaged or not fully inserted in the chamber, or the cartridges get dirty.

Clean the cartridges, or re-insert the magazine properly.

Change the magazine in case of damage.


Malfunctioned cartridge, or dirty firing pin hole. The lubricant is possibly left in low temperature.

Get the specialized workshop clean and inspect the rifle.

A shot sounds "weak."

There is no powder load in the cartridge, or the power gets moist. It can cause severe damage to the barrel.

Unload the gun and check whether the bullet is obstructed the barrel.

The cartridge case is not ejected.

The chamber, ammunition, or extractor is fouled (dirty); or the improper lubricant is used in low temperature.

Clean the chamber, ammunition, or extractor.

Change the lubricate with a recommended one.

Final Thoughts

We have given a closer look at every function of the CA 805 Bren S1. To say, this rifle is worth to invest. If you run into any problem stated above, calm down and follow the guide to fix it all. Remember to follow the Safety Instructions whenever you use, test or maintain the gun:

  • Keep the gun pointed in a safe direction
  • Do not turn the gun towards you or anyone else
  • Do not place your hands ahead of the barrel

Don't forget check out my recent post about best ar15 scope for shooting here!!!

2 thoughts on “What Is Cz 805 Bren (Review) – Any Reported Problems With It? And How To Fix?”

  1. I own both the Bren 1 in 5.56 & a Bren 2 in 7.62 x 39. Contrary to popular opinion, I prefer my Bren 1. CZ listened to the talking heads and modified the take-down pins, gas piston and charging handle, etc. between the two models. My only problem with the Bren 1 is that it seems to be hard on magazines. I’ve sheared the feed lips off of a polymer Pro-mag which Pro-mag graciously stood behind their product and replaced. I’ve been shooting aluminum GI mags ever since and noticed that the bolt is starting to gouge the back of my mags. That being said, I shoot my Brens more often than any of my other rifles.


Leave a Comment