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Few would argue that the Mauser action is anything less than a classic. The CZ 527 American Synthetic Suppressor-Ready (527 SR) utilizes the classic Mauser action while offering modern flair in terms of caliber options and suppressor adaptability.

The CZ 527 action is a true micro-Mauser—not a standard Mauser action that has been chopped and re-welded. This makes for a svelte-handling rifle. The CZ 527 SR features an American-style synthetic pattern stock, a sportier profile hammer-forged barrel, single-set trigger and a threaded muzzle.

CZ has further upped the ante with interesting chambering options in 7.62×39 Soviet and 300 AAC Blackout (SAAMI short name: 300 BLK). This might surprise some, because both of these chamberings are associated with military-style rifles; but both cartridges are natural candidates for use in conjunction with the micro-Mauser bolt action. The 300 BLK, in particular, is a natural match to a rifle intended to accommodate a suppressor and is the cartridge chambering tested for this article.

Credit must be given to CZ for coming up with this for the American market; there are few mainline firearm companies offering either round in a bolt-action rifle format—let alone with a 5/8×24 threaded barrel ready to accommodate mounting a suppressor.

The CZ 527 SR has a threaded barrel to accommodate easy adaption to suppressor use.

What role is the CZ 527 SR intended to fill? As with most things related to firearms, the answer depends on the individual situation. Factors such as mindset, personal preference, skill level, training, need to fulfill multiple roles and even legal requirements all come into play regarding rifle selection for defense.

The CZ 527 SR, with its Mauser action, is definitely at home in a hunting role. CZ’s decision to offer a suppressor-ready bolt-action 300 BLK opens up multiple roles. The CZ 527 Suppressor-Ready and 300 BLK were made for each other.

The CZ 527 SR has a classic sporter appearance, taking full advantage of the micro-mauser action to create a lightweight, smooth-handling rifle.


CZ-USA, based in Kansas City, Kansas, is the U.S. subsidiary of CZ and the importer of CZ firearms. CZ, itself, is based in the Czech Republic and dates back to 1919. In 1991, it was one of the first East European corporations to emerge from the post-Soviet era to compete in the West. This company is one of the world’s largest firearms manufacturers, employing more than 2,000 people and selling its wares in more than 60 countries. CZ products include handguns, shotguns, sporting rifles and military weapons.

The CZ 527 SR has a classic sporter appearance, taking full advantage of the micro-Mauser action to create a lightweight, smooth-handling rifle. Truly a shortened profile, the CZ 527’s Mauser action is only 6 inches long and saves at least 1 pound over a standard Mauser bolt action.

The CZ micro-Mauser action is perfect to create a lightweight, great-handling rifle. Truly a shortened profile, the CZ 527’s Mauser action is only 6 inches long and saves at least 1 pound over a standard Mauser bolt action.

Positive functioning was never an issue: CZ has fitted the 527 SR with a 16.5-inch, hammer-forged, free-float barrel with threaded muzzle. CZ barrels are of excellent quality (refer to the included test group accuracy sidebar on page 39). Sling swivels are standard features on the CZ 527.

The CZ 527 SR rifle is fed from a detachable, five-round magazine. A better mixture of classic bolt with American utilitarian cartridge would be hard to come by.

Comparing several sources of information, standard velocity 300 BLK 115- to 125-grain ammunition exceeds the ballistics of the 7.62×39 and eclipses the 5.56mm in both ballistics and terminal punch. At 300 meters, the 300 BLK has approximately 17 percent more energy than the 7.62×39. The 300 BLK from a 9-inch barrel has the same energy at the muzzle as a 14.5-inch-barreled 5.56mm M4 and surpasses it as ranges extend.

Not surprising (because AAC is in the suppressor business) is the ability to choose 300 BLK subsonic loads for optimal use with a sound suppressor. The ability to access either supersonic or subsonic factory ammunition offers the shooter great flexibility. Whatever roles the CZ 527 Suppressor-Ready is considered for—hunting, personal defense or sport—it fits the bill.

Numerous 300 BLK ammunition loads were used with the CZ 527 SR, including standard and subsonic loads.


Ammunition tested with the CZ 527 Suppressor-Ready included Hornady 125-grain HP, SIG Sauer Elite 125-grain and 220-grain Match subsonic, and Black Hills 125-grain and 220-grain OTM. What distinguishes the 300 BLK is its ability to access standard supersonic rounds for typical hunting or longer-range engagements superior to 5.56mm while maintaining the trump card of subsonic ammunition for more discrete specialized work.

A SIG Sauer Tango 6 1-6x24mm optic was mounted via CZ 30mm rings. One crucial improvement with the CZ Mauser is its square bridge design that allows for an integral scope base. The CZ rings mate up right to the action for solid attachment and help ensure reliable scope zeroes. The Tango 6 offers a 1x illuminated reticle setting for fast target acquisition at close range with both eyes open. A quick turn of the knob to 6x enables longer precision shots.

CZ’s decision to manufacture a “square bridge” Mauser with integral scope bases will aid in its acceptance by bolt-action rifle connoisseurs for whom a scope is standard equipment.

The SIG Sauer Tango 6 is loaded with high-end features, such as an adjustable, illuminated MOA reticle and extra-low-dispersion glass combined with high-transmittance glass for outstanding light transmission and clarity. In addition, the turrets are resettable, lockable and zero stop. SIG Sauer offers various power ranges and options in the Tango 6 model lineup: different reticle styles, MRAD or MOA turret adjustments, and first or second focal plane, to name a few.

The whole package came together when the SIG Sauer SRD762-QD suppressor was mounted on the rifle via SIG Sauer’s Taper-Lok mounting system. After all, suppressor use is the point of a rifle chambered in 300 BLK. The SRD762-QD weighs 17 ounces and measures 7 inches long and 1.625 inches wide. It has a sound rating of 140db and is rated up to .300 Winchester Magnum.

A SIG Sauer SR762-QD suppressor and proprietary SIG Sauer Taper-Lok muzzle attachment.

The subsonic 300 BLK rounds were “movie quiet” out of the CZ 527 SR with the SIG suppressor mounted. The Tango 6 scope’s Horseshoe Dot reticle allows for both supersonic and subsonic aiming points to be established.

The CZ 527 sports a unique, single set trigger design. This definite European feature might not be as familiar to U.S. shooters, but it proved useful when firing from the bench. The trigger is set by pushing it forward; once set, it offers a trigger pull weight of 2 pounds. However, the normal trigger pull was a quite acceptable, crisp 4.5 pounds and certainly was no detriment during accuracy testing at the range.


The CZ 527 Suppressor-Ready bolt action and the 300 BLK make for a very appealing, distinctive combination. There is no need for a super-magnum rifle and a mega-zoom scope with a hyper-complicated reticle. I find it hard to believe that anyone using this rifle chambered in this cartridge would ever be undergunned or at a disadvantage when hunting deer-sized game or pressed into a defensive posture. It will find a niche for itself in the American market, appealing to rifle lovers for its efficiency.

The users already familiar with the 300 BLK cartridge will appreciate the performance enhancement offered with the CZ 527 SR in terms of accuracy and ease of suppression. As for quietness, nothing compares to a bolt action with a quality suppressor attached and firing subsonic ammunition. Because the action is manual, a bolt action takes that noise element out of the picture.

The Subsonic 300 BLK with a quality suppressor such as the SIG Sauer SRD762-QD is a potent combination.

I was quite surprised by the accuracy premium offered by the bolt-action CZ 527 SR combined with SIG Sauer optics.

The CZ 527 SR was tested for accuracy from the bench and from around barricades and other obstacles, with and without a suppressor mounted, to get a better appreciation of its handling and performance. Steel targets were smacked with ease out to 250 yards, either standing or using field-expedient rests. The increased accuracy of the CZ 527 SR with SIG Sauer Tango 6 optics paid great dividends.

While by no means rivaling a semiautomatic for firepower, the detachable, five-round magazines were handy to recharge the CZ 527 after the last round. As expected from a bolt action, no malfunctions were experienced. The safety selector was different compared to U.S.-based rifles with the safety engaged by pushing it forward and releasing it by moving it rearward. The safety made no audible noise when manipulating it—an important consideration for hunting or defense. Recoil was not a factor; nearly 150 rounds were fired with no issues or detriment to the accuracy experienced.

The subsonic 300 blk rounds were “movie quiet” out of the CZ 527 SR with the sig suppressor mounted.


The CZ 527 SR is a rifle that can serve in multiple roles, such as sport, hunting or defense. The 300 BLK chambering is a definite positive. It offers both performance and flexibility in adapting to a variety of situations. More and more load options are being developed for the 300 BLK, including premium hunting bullets.

A CZ 527 SR 300 BLK subsonic with a suppressor is the ideal candidate for defensive use.

It’s an impressive rifle/chambering combination that offers great versatility—and in a very handy package. With the ability to attract users from a variety of backgrounds, the CZ 527 Suppressor-Ready should prove a popular offering from CZ USA.

Performance Results


Average (fps)

Average (inches)

Best (inches)

Black Hills 125-grain OTM 2,210 1.5 1.0
Hornady 125-grain HP 2,335 1.66 1.33
Black Hills 220-grain OTM 1,010 1.75 1.25
SIG Sauer Elite 125 grain 2,220 1.33 1.25
SIG Sauer Elite 220 grain 995 1.25 .88

Note: Velocity was an average of five shots. Accuracy was measured using three five-shot groups at 100 yards.

CZ 527 American Synthetic Suppressor-Ready


Caliber: .300 Blackout (7.62×39 is another option)
Barrel: 16.25 inches
Overall Length: 35 inches
Weight: 5.9 pounds
Sights: Integrated 16mm scope bases (squarebridge Mauser) with 1-inch or 30mm rings available
Stock: Black polymer Sporting pattern
Action: Mauser bolt action
Capacity: Detachable five-round magazine
MSRP: $748

Contact Information

(800) 955-4486

(603) 610-3000

(605) 348-5150

(800) 338-3220


Editor’s note: A version of this article first appeared in the June 2017 print issue of Gun World Magazine.