Croatia is a leading developer in the growth of small arms design.
The development of the VHS started in 2005, and an early prototype surfaced in 2006. It features an all-polymer exterior and chambers 5.56x45mm NATO. The rifle weight is a feather-light 5.06 pounds empty. From the outside, the early VHS prototype somewhat resembles a bullpup variation of the HK G36. The influence is probably due to the Croatian military use of the German-made G36 and G36K by its uniformed elite. These troops are serving UN missions and fighting the War on Terror in Afghanistan as the newest member of NATO. Most of the Croatian military is still using locally produced AKMs.
Interestingly, the early Croatian VHS design used a direct gas-impingement action with a multilug rotating bolt. The bolt carrier rides on two parallel guide rods to eliminate any carrier tilt. The gas tube passes between these two parallel guide rods. Unlike the Stoner impingement system on the M16/AR-15, excess gas does not vent out of the rifle through an ejection port. Instead, the patented Croatian system vents the gas into a tubular chamber behind the action. In turn, this gas chamber acts as a pneumatic buffer to slow down the bolt group for a soft stop without hitting the back of the receiver. Then, the highly compressed gas in the chamber acts as the bolt spring to return the bolt group forward. The system lacks a conventional coil return spring. Although this clever gas/buffer system isn't actually new, it was first used in the Russian Afanasev-Makarov 23mm aircraft auto cannon in the early 1950s.
The VHS bullpup went through a complete redesign both internally and externally in 2007 — 2008. The direct gas-impingement action and complex gas/buffer system were replaced by a conventional short-stroke gas piston system with bolt spring. The new bolt group features a long bolt-carrier extension like the one found in the FNH SCAR. The new gas system consists of an adjustable gas regulator and a short-tappet gas piston with return spring.
Externally, the updated VHS took the shape of the French FAMAS, and it even copied the distinctive-looking croissant-shaped large carry handle. There are numerous mounting holes on the polymer exterior for installing Picatinny rails on the VHS bullpup.
The controls have also been updated. The charging handle is relocated inside of the large carry handle. The swivel-out function was inspired by the HK G36 charging handle, but the one on the VHS is non-reciprocating. The bolt release is located on the upper left side of the pistol grip, and it can be manipulated with the user's thumb. The selector is inside the triggerguard and in front of the trigger in a similar fashion as the FNH P90 and F2000. The middle setting is the safe position. Turn the selector to the left for full automatic and to the right for a single-shot semiautomatic.
The VHS is being made in two variants: the VHS-D (dugi means "long") with a full-length 19.7-inch barrel and the VHS-K (kratki, or "short") with a 15.7-inch barrel in the carbine size. The unit cost is the American equivalent of $2,100. Seven magazines, cleaning kit, sling and user's manual are included with each rifle.
Fifty units of the initial VHS trial production were sent to Croatian troops in Afghanistan for battlefield testing in 2008. Forty units were sent to the Jamadol military range for environmental, durability and destruction trials between March and April 2009. With more than 30,000 rounds fired, the Jamadol test was a success. The VHS bullpup design was proven to be functional in such battlefield conditions, earning the reputation that it could run without lubrication for an extended period. Satisfied with the results, the Croatian Ministry of Defense signed a contract with HS Produkt for the 1,000-unit first production batch on May 15, 2009. A total of 20,000 VHS bullpups are intended for procurement by the Croatian military as replacements for all of the AKs and other rifles in service.