Rusan Picatinny rail - CZ 550, 557 / 600 ZKK (20 MOA)

Introduction

Picatinny rail consists of slots with 5.23 mm spaces between one another, which means that it can be used across its entire length. It is simple to mount and interchangeable – if something is made for a Picatinny rail, it will fit regardless of the manufacturer or manufacturing date. It is affordable, resilient and reliable – this is why it so commonly used by professionals and military. Because of all its great qualities, Picatinny rail has been dominating the rail market in the recent years.

Picatinny is a big step forward from the Weaver standard. Weaver has a few predesignated slots while Picatinny has slots all over its surface, allowing the device to be mounted wherever the user finds it fitting. Weaver's slot is 3.8 mm wide, which is why ring mounts made for a Weaver rail will also fit on a Picatinny rail while ring mounts made specifically for a Picatinny rail will not fit on a Weaver rail. This is one of the main reasons why Picatinny is a far better mounting solution.

Rusan, a company from Croatia, is one of the manufacturers of Picatinny rails. They make mounts from steel and aluminium and provide buyers with a wide selection of Picatinny rails for various rifles. They are made from high quality deep blue finish steel. Picatinny Rails include screws with appropriate thread for the corresponding rifle. Rusan covers 10 years of warranty for all its products.

20 MOA Inclination

20 MOA inclination is only needed when the scope runs out of elevation. For example, when shooting at the range of 100 m, shooter gains 58.2 cm / 100 m of additional elevation range with a 20 MOA mount. This is approximately 5.8 Mrad of elevation. To make things even clearer – if the target was placed at 100 m, the scope with 20 MOA inclined rail would aim to the center of the target while the rifle’s barrel would aim 58 cm higher than the scope. This gives the shooter extra elevation needed for long range shooting. If you plan to shoot on distances longer than 600 meters, use of rail with 20 MOA is greatly recommended. There is no negative effect of the inclined Picatinny rail in the mounting setup if you only shoot on shorter distances. The same goes also the other way around, since if you don’t shoot on extreme distances then Picatinny rail with inclination is not needed.

About the rifle

CZ stands for Ceská Zbrojovka. The company headquarters are based in Uhersky Brod, a small town in the Czech Republic. The present day CZ was set-up in 1936 as a subsidiary of CZ Strakonice, which was, in turn, a subsidiary of Zbrojovka Brno – the armaments industry grew rapidly in the new Czechoslovakia at the time, and Uhersky Brod seemed like a great location since it was secluded and lay beyond the range of German bombers. In 1939, German forces occupied Czechoslovakia and the company was renamed to Böhmische Waffenwerke. Until 1945, they made machine guns LK-30 and MG-17 for the German army. After World War II, Russians gained control of the entire region and the company was nationalized by the communist government. Along with firearms, the company produced parts for the CZ 125 motorcycle and parts for sewing machines. In 1957, they started producing Model 58 assault rifle, a Czech version of AK-47. In 1961, the renowned Skorpion machine pistol entered production. The famous CZ 75 pistol was launched in 1975. Ceská Zbrojovka became an independent company in May 1992 when the “iron curtain” fell. Today, they are one of the biggest manufacturers light firearms. CZ 75, the famous pistol, is used as a basis by many other firearm manufacturers.

CZ 550, a bolt-action rifle, was first introduced in 1997 when it replaced CZ 537. It features a fixed magazine, but some models, chambered for .22-250 Rem., .243 Win. and .308 Win. can also come with a removable magazine. CZ 550 has an emergency gas pressure release valve on the right of the receiver. There are four locking lugs on the bolt. It has no mounting holes on the receiver; instead, the receiver is equipped with a 19mm dovetail for mounting purposes. CZ 550's action is controlled-feed. The safety catch is located on the right of the receiver, behind the bolt lever. CZ 550 rifles are chambered for .22-250 Rem., .243 Win., .308 Win., 6.5x55, .243 Win., .270 Win., 7x57, 7x64, .308 Win., .30-06 Sprg. and 9.3x62 (caliber range depends on the CZ 550 model). CZ 550 Magnum is chambered for 7mm Rem. Mag., .300 Win. Mag., .375 H&H, .416 Rem. Mag., .416 Rigby and .458 Win. Mag. CZ 550 Scandinavian is a little bit different from other CZ 550 rifles – it has a raised back to its stock. It also has no dove-tail on the receiver but 4 mounting holes, two at the front mounting surface and two at the rear mounting surface.

Rifles CZ 550, CZ 537, CZ 557, Brno ZKK 600, Brno ZKK 601, Brno ZKK 602 and Brunner 19 have a 19mm dovetail on the receiver for mounting purposes.

This mount is made for all CZ 550 rifles with standard action length (it is not suitable for CZ 550 Scandinavian and Magnum versions) and Brno ZKK 600.

A: / (no holes)
B: / (no holes)
C: / (no holes)
BHU: 0 mm
Fi: /
R1: Prisma 19
R2: Prisma 19

Mounting instructions

Remove all the stains (grease, oil etc.) from the rifle's receiver with a cleaning fluid (acetone). Once the surface is clean and dry, check whether the screws match the rail and the holes on the receiver. Make sure that the Picatinny rail is compatible with the rifle by inspecting the mounting holes on both. Before mounting the rail permanently, apply a minimal amount of thread-locking fluid 278 or 648 on screws and contact surfaces. Be careful not to get the fluid in or near the mounting holes. Carefully clean the remaining excess fluid around the rail with a cleaning fluid. Using a torque driver, screw the screws appropriately (up to 2.2 Nm) – do not overtighten.

Warranty

The product has a warranty period of 10 years.