First impression

The replica is delivered to us in a standard box made of grey cardboard with a big blue Viper Tech Company sign. Inside, in a cardboard insert, is the replica and a CO2 magazine.

The first impression is great. When we take the replica into our hands we do not feel that it is a toy. This is because of the replicas weight: the SR-16E3 Carbine weighs 3576 g with the magazine inserted and 2958 g without it. If it were not for the magazine's design, it would be difficult to distinguish the replica from a real firearm at first glance. All parts are well fitted together, nothing crackles nor rattles. The bolt carrier moves with proper resistance and sound and the trigger act the same as in the real firearm.

The upper and lower receiver

The upper and lower receiver are made of 6061 aluminium. It resembles the classic AR-15 design but has additional ambidextrous parts: the fire selector switch, the magazine release button and the bolt-catch. The upper receiver has no markings. It has a Picatinny rail on top. On one side of the lower receiver there are markings engraved. The other is completely flat. At the height if the magwell is the Viper Tech logo, a cobra inside a triangle, and a Mk X2 cal. Multi marking. At the height of the fire selector switch there is the VCXII-XX0008 Made In Taiwan marking.

The stock

The polymer Special Forces type stock has a dark earth colour and looks very robust. We did not notice considerable slack: the stock moves on the guide without any problems and does not wobble sideways after locking into place. The guide allows to set the stock in five different positions. The mould is very good, there is no flash or other defects.

The pistol grip

The polymer robust pistol grip is also dark earth in colour. It is mounted on a single hex screw and has a classic design known from the basic AR-15 model. It has a rough texture on the sides, vertical ribs on the back and a hump on the front. All this facilitates a firm and stable grip.

The external barrel and muzzle break

The replica has a non-standard external barrel, 378 mm long, which has been made of steel. Its non-standard design its the result of a atypical way is is connected with the upper receiver and the presence of a port that gives us access to the hop-up adjustment. The barrel has an inner thread on its exiting end, into which an adapter is screwed in. Only than we can mount a muzzle break. The replica we got had a standard, steel, M16 type flash hider with a counterclockwise thread. The barrel has a fake low profile, detachable gas block and a fake gas tube.

The front

The front used in the replicas is a copy of the URX 3.1 Forend Assembly, 13.5″ by Knight’s Armament Company. Anodized, black front has been made from aluminium. In addition the manufacturer supplies polymer dark earth panels as part of the set. They have a rough texture which facilitates the comfort and firmness of gripping it.

The front is made of two parts. After unscrewing side hex screws and pressing the position setting button situated in the bottom part of the front near its connection point with the receiver, we can slide the bottom part of the front off. First of all, this gives us access to the hop-up adjustment, but also allows for unscrewing the external barrel from the upper receiver. Unfortunately, this is possible only when we have a special wrench which is not very popular therefore this procedure can be troublesome.

The magazine

The magazine used in this replica is a classic steel STANAG type real-cap magazine holding 30 BBs. Its weight (632 g) is close to a fully loaded real steel version. It gives excellent training possibilities not only in the area of weapon's handling but also in the area of realistic weight distribution while carrying the magazines in the pouches. Each magazine houses a CO2 capsule which powers the replica and allows for great performance even in cold weather.

After removing the magazine's base plate we can exchange the CO2 capsule. T do this, we must unscrew two hex screws: one sets the capsule in the right position, the other is responsible for pressing it against the intake valve.

After unscrewing the screw in the rear part of the magazine we can take out all the inner parts of the magazine from the shell. First we pull out the BB feeding system. After that we get the pneumatic system out. All the parts look good: there is a purple aluminum chamber with a intake valve chamber, which has a double O-ring, screwed into it. The weakest part of the magazine is a plastic piece which lock the bolt carrier into the rear position after the last BB had been fired. When inserting the magazine into the carbine, especially when the bolt carrier is in the rear position, one must be very careful. If the insertion is done too strongly we can break this part - this is a very serious drawback.

Replica disassembly

The replicas is based on the AR-15 design therefore its disassembly is exactly the same is in the real fire, that is by slide out the pins. After the rear pin is slid out we can break the replica in half and gain easy access to the bolt carrier, the buffer, the trigger system and so on. After sliding out the front pin we can split the upper and lower receiver completely. The pins remain in the upper receiver after the operation therefore we do not have to worry about loosing them.

The hop-up chamber

Access to the chamber is not a well designed feature. To adjust the hop-up we have to unscrew 8 hex screws in the front and insert a narrow hex wrench (or any other tool that will fit) into a hole in the underside of the front.  This allows us to take it off and only than we gain access to hop-up adjustment.

The adjustment itself is done using a rotating ring, a feature similar to other rotary hop-up chambers, which is situated in a port of the external barrel. Yet here the mechanism adjusts the pressure of the lever that presses against a steel ball that acts as a spacer.

To get to the hop-up bucking we must first unscrew the barrel nut at the replica's front, which is not an easy task taking into consideration tight space and a special wrench required. When we manage to do so and disassemble the external barrel we have the ability to take out the hop-up chamber. To take the first part of the chamber off, which is responsible for stabilizing and supporting the hop-up lever, one must unscrew three hex pressure screws. The next step is to unscrew another two pressure screws which stabilize the proper alignment of the inner barrel in the chamber.

A surprising fact is that the bucking is glues to the inner barrel which makes its removal without damaging it almost impossible. The black bucking of medium hardness is a hybrid of designs meant for AEG and gas powered replicas. Limited access to spear ones may be a problem when we decide to replace it. Its spinning nub is the same as in the PDI W-Hold buckings.

The inner barrel

The inner barrel is 415 mm long. What is surprising it is a standard AEG inner barrel.

The bolt carrier and the bolt

The heavy, metal bolt carrier (292g) together with the bolt are, at first glance, identical to the ones used in real firearms. The replica is given away only by the gas intake port at the bottom of the bolt carrier. The said part is made of steel and servers both as the piston and the nozzle in the blow back system. A novelty in Viper Tech's offer is the ability to exchange the 16mm bolt for an 18mm one, which is used when the replica is powered by Green Gas.

 When removing the bolt carrier, one must be careful as not to loose a small metal part that falls out of it as it is responsible for aligning the bolt in the proper position. The bolt carrier does not lock into place as in the real firearm. This is the result of its design and the need to be fed CO2 from the capsule inside the magazine.

The buffer and its spring are housed inside the stock guide and work in the same way as in the real firearm. Even their shape and machining are very close to the original. Similarly, the buffer safety latch is in the same place and works in the same manner, preventing the buffer to pop out when the weapon is disassembled.

The trigger group

This part of the replica will be pleasing for people that like realism. Lets not be fooled, the replica's lower receiverwill not work with the upper receiver of a real firearm yet, at first glance, it would seem that way. What prevents it is a metal part which houses the bolt-catch and the mechanism that hits the magazine's outlet valve. On top of that there is the hammer that stops its action at 45° and magazines from the real firearm, which do not fit into the replica.

The way the trigger, the hammer, the delayer, the ambidextrous fire selector switch and magazine release button look and work are based directly on the real firearm. The exception from this rule is the ambidextrous bolt-catch which differs from the one used in the real firearm. All of these parts, along with the springs, are made of steel, seem to be robust and perform their function adequately.

The manufacturer even took care of such details as the Combat Trigger Guard Assembly which has an engraving of the Knight’s Armament logo. The trigger guard is made of aluminium and its design facilitated proper operating of the trigger.

Shooting

The shooting, as well as handling the replica, is very similar to a real firearm. The replica is loud. The BB, after leaving barrel, fly with a straight, stable trajectory, sideways deviations are rare. The replica generates about 510 FPS and has a ROF of 13 RPS. The kickback, which the Viper Tech provides, is only slightly weaker than the real firearm, which will be very meaningful for users looking for a training reaplica.

Summary

An ambitious idea of Viper Tech, to create a hyper-realistic rifle, has been put into practice with quite a good result. The replica will prove itself as a training weapon: its handling and overall workings are the same as in the real firearm and quite a considerable kickback (only slightly less powerful than in the real firearm) increases the feeling of realism. The heavy magazine, which weight is similar to a real loaded one, is powered by CO2 capsules. But it turned out to be the weakest part of the replica and it is not a problem of leaking gas. The part that is responsible for keeping the bolt carrier in the rear position, after the last BB has been fired, is made of plastic and can easily be broken by accident. Despite this, the replica will be appreciated by people who want to take their training session outside of a shooting range. How will this replica fare in an airsoft game is up to the user's preferences. People that like mil-sims will be very satisfied but the ones that prefer more action oriented games might find out that 30 BBs in the magazine is not enough when faced with a person using a hi-cap. Yet, its better to shoot one BB that hits its target then spray a whole bunch of them but hit nothing. 

We would like to thank Viper Tech for granting us access to their replica