BOYI: BI-3581

Boyi/Dboys is one of the more profiled names in the ranks of the Chinese manufacturers. What is the deal with the double name? After some research, I was offered an explanation that this is the same company: replicas are sold as Boyi and accessories under Dboys name. They introduced themselves in the mid 2006 with parts and accessories; replicas of M4 family followed, which established them among more visible Chinese manufacturers.

CASV was introduced in the Autumn of the 2007 and- as the name suggests- it comes with preinstalled CASV front end. CASV was developed by Vltor, (division of Abrams Airborne Mfg. Inc.) under request from us United States Navy. Basically it is a free float fore end system, designed to be mounted on flattop, carbine length weapons. It has a removable lower hand guard, which enables mounting of M203.

Official name of this replica is BI-3581, but for the sake of clarity (not to mention the sake of sanity of the author of this review) we will call it Boyi CASV or M4 CASV for short. Packaging is a bit special, but very nice. There is no Styrofoam box in traditional sense of the world. Cardboard is folded and reinforced with strategically placed Styrofoam to form a visually pleasant, not to mention efficient protection during transport.

Package contains all the usual bits and bobs, which are expected from Chinese replicas: replica itself, battery, battery box, sling, vertical grip and charger. First impression is a bit ambivalent: visually replica looks extremely appealing, but everything rattles and generally looks it will all fall on the floor, including rails on the CASV, which were only half screwed in. First order of things is to tighten all the nuts and bolts. I suspect that this is not just usual shock from the transport, rather than workers in Boyi’s factory does not take very long to screw the bolts in with more than hands. Never mind, couple of minutes later, nuts and bolts are tightened. Once put together, the replica is rock solid. Plastic parts (stock, pistol grip) have a greyish tone and a very nice texture. Metal parts include everything except body, stock and pistol grip.

Marui’s M4A1 has two piece outer barrel, which is not the best solution, as the dreaded barrel wobble developed during the course of use. Boyi CASV has worked around this problem with single piece barrel. Sadly, it is not true one piece, but it is comprised from two pieces, held together by a screw. And you guessed it, screw has a nasty habit to undo itself, leaving us with a bit of a barrel wobble. This is a probably a good way to cut manufacture costs (longer the barrel, higher the costs) but acts detrimental to the overall sturdiness of the replica’s front end. This is probably a problematic part, since VLTOR is in essence a free floating system and screw needs a constant checking and re-tightening.

As mentioned, CASV is a free floating system, which is very much beneficial for accuracy of weapons, equipped with CASV fore grip. In layman terms, this means that barrel not in contact with fore grip, which is beneficial to the accuracy. In airsoft, that spells trouble. Double trouble, if plastic body is used. It is a plus that Boyi CASV front end is extremely rigid and moves minimally. Solution is ingenious, but in rather primitive: two screws, which hold CASV rails are long enough to press against the barrel as additional stabilisation. This results in stable front portion of the replica, even several rough encounters with the trees.

Enough about negatives, outer barrel has another, much nicer option. It can be unscrewed right after front sight in order to simulate shorter, 10.4 inch barrelled weapon. Naturally, you will need a new inner barrel. Phantom flash hider is a replica of Yankee Hill’s product. Its main advantage is excellent elimination of flash and it it most often used while wearing night vision devices. Additional bonus is that its bezel is sharpened and can be used in hand to hand combat (the coveted muzzle thump). However, diameter of the flash hider prevents installation of Halo suppressor, so you will have to look into screw on suppressors.

Front sight is standard M16 type; rear sight flip-up type. It works and it is fully adjustable, but its springs are not as stiff as they should be. In other words, after you disengage the brake it moves lazily in the extended position.

Rear sight is fully adjustable, but again it doesn’t give a very clear report, as adjustment is very soft.

Finish on the metal parts of the replica is soft and it chips easily; this should come as no surprise, as it is a fairly standard feature of Chinese made replicas. Die-casting of the metal parts is very acceptable; rails on the CASV interface are even, with sharp edges.

Boyi CASV comes with sling adapter, which is very nice feature (and if you don’t have one on your M4/M16, you should seriously look into buying one).

Stock is law enforcement type and buffer tube has 5 points of retraction. Plastic parts are again nicely made, not too shiny, with slight texture.

Fire selector audibly clicks into position. Charging handle opens bolt cover, which enables access to the HopUp adjustment dial. Spring is stiff and bolt covers slams against plastic body very loudly.

Vertical grip is bit on the cheap side. Casting is not bad, but there are visible seam lines. Quick intervention with file or sharp knife is in order. When installed, it wobbles a bit. It is barely noticeable, but it is there. Grips from other manufacturers (Marui, Classic Army) are rock solid, which proves that problem is not in the dimension of the rails, but rather grip itself.

This is first battery box I’ve seen with quick and reasonable speed of change of battery. Quality of the box is not bad at all. It looks a little bland (some stickers would be nice) but otherwise bears a good resemblance to PAQ unit. Small details such as various buttons and inscriptions are included. Battery change is simple and efficient. On/off button secures the back plate of the battery box, which means that you have to unscrew the button and remove tha back plate. There is enough space for small battery (included) or custom made battery. As I’m not the biggest fan of battery boxes I stored battery in the lower portion of the CASV hand guard, where is just enough space to squeeze in the mini type battery. And if you do, please be careful when closing the CASV together. Edges are rather sharp and I managed to cut the cable…

While the quality and most importantly, speed of battery change is not questionable, I’m still seriously thinking of installing Boyi Modstock.

Sling is useful, as it is made out of thick nylon. While it is fairly ordinary three point sling it is a part of the package and you need not to spend additional money to purchase one. It has few minor niggles (plastic D rings have tendency to turn on the side) but this are really minor problems.

Boyi has reportedly some problems with quality control. This may well be the case, but tested replica was operating as expected. Gearbox is cleanly die casted. It is almost customarily by now for Chinese manufactures to use metal bushings.

Gears are -as can be expected- from XYT foundry. Re-shimming was not necessary, as the gears are running very smoothly. Gearbox was very lightly greased; actually, contact surfaces were well (maybe even too well) oiled. Gearbox is very neat.

And now for the weak link in the mechanics of Boyi M4 CASV. Motor appears as very weak and is prime candidate for the change. Coupled with barely satisfactory original battery it has trouble maintaining a decent rate of fire.

I’ve used this replica as primary replica on our skirmishes (as I always do with test specimens, since it is hard to write a semi decent review without hands on experience). I was having great fun using it. For some players Boyi CASV may be a little too hot, as it shoots between 330-340 fps.

As always, there is question who is potential buyer of this replica. For one, those who like the aesthetics of CASV equipped replica for sure; secondly, players who need second replica and maybe use it as loaner. In any case, it is wise to test it and to correct possible problems. Another word of caution- until recently, Boyi replicas were a bit of hit and miss. Their track record is much better with metal bodied replicas.

Let’s recap: what needs to be changed in order to make Boyi M4 CASV truly competitive? This may differ from replica to replica, but general consensus is that in the first series of their replicas (plastic bodies) main culprit for sub standard performance is the motor, which should be changed ASAP. HopUp rubber- to achieve consistency- can also be changed right out of the box. Wiring is functional, and If you have extra time, inclination and spare parts, it is wise to change it.

Gearbox is very good, internal parts are of good quality. No complaints there.

Original battery is not the best (1100mAh) and again, I’d change stock from LE type to Crane or Clubfoot type stock.

There you have it. Final verdict? If you look down on products from China mainland- stop it and stop it now. They are breathing on the neck of the first tier manufacturers and all they need is a bit of quality control- and they will be as good as them. At one third of the price.

Test item provided by CRW Airsoft