GURZA project was the logical continuation of Italian factory-made pneumatic guns modernization. GURZA project guns have barrels of stainless steel, which distinguishes them from the already known pneumatic vacuum upgrades of UBL of factory-made “Italians”. Vacuum permits to try installing barrels of different diameters (not interfering with water shot in the barrel). Barrels with piston diameters of 10 mm, 12 mm, 14 mm, 16 mm and even 18 mm were tested. … and dynamics produced by shooting with a 10 mm barrel gun gives an extremely nice feeling. Thus, for example, a modernized MARES SPARK 55, in terms of 18 kg harpoon pressure, easily goes through a 12 kg European carp by standard 7 mm crossbow harpoon without “sly” tips. Hitting power reducer is generally retrieved. Shot dynamics decreased with barrel diameter increase. All Italian pneumatic guns with 11 mm and 13 mm barrel can be upgraded without exception. However it is possible to single out the most successful models in terms of modernization, for example MARES Spark/Cyrano. Stainless steel barrel with high-quality treatment of internal surface in combination with the “right” piston and the “right” oil yields the smallest friction ratio of the barrel and piston unit at 25 kg harpoon working pressure and is equal to 0.015. For comparison, the friction ratio of a factory barrel and piston unit (duralumin barrel) of MARES Cyrano under the same conditions may reach 0.25, i.e. sixteen times more! What do these figures mean in action? First of all, the gun efficiency factor is increased. It is well-known that gun efficiency is the relation of energy consumed in the course of gun loading to the released energy at the moment of shooting. This in its turn means that there will be no need for “swapping” the gun in order to achieve maximum efficient shooting range. Reduction of gun initial pumping will decrease kickback when shooting and therefore increase target range. The form of sear hook, height of sear hook, as well as the diameter of the piston hook knob were also changed. This made the release more short-stroke and smooth without increasing the risk of self-inflicted wounding if the gun falls or is hit accidentally. The collar cuff of the piston ensures a progressive friction ratio which is directly proportional to air pressure in the gun receiver. I abandoned the idea of the collar cuff in the piston for GURZA project. Leak tightness is ensured by one ring. Piston weight is reduced almost twice, which is important for the service life of the latter. Use of polypropylene in the piston manufacture rules out splitting and “swelling”. You can watch the actual result in the video Shooting was performed at 5 m and 6 m distance (from harpoon tip to the target) with a modified MARES Cyrano 970 with 14 mm barrel diameter and 7 mm harpoon diameter at 3 l plastic container with sand hung on a harbor boom. It can be seen in the video that the container is flying up and down due to water roughness, so there was a semblance of a moving object. For more realistic performance the shooting line was done bottom-up, i.e. the shot occupied the position between stones at 4 m depth and the target was at 1-1.5 m distance from the surface. Harpoon pressure made 22 kg – the gun was loaded simply by hand. The number of hits/misses out of ten shots was: at 5 m distance - 9/1, at 6 m distance – 7/3. However these results mostly characterize me as a shot. Someone may make 10/0 at 7 m distance. Who knows.

The model debut took place at the APNOS cup competitions in Sevastopol on 27-28.06.2009 and on 04-05.07.2009 at the championship of Ukraine. Alexander Galaktionov became the champion of Ukraine in underwater hunting. Alexander’s arsenal includes four Italian guns of various length from 50 cm to 97 cm, enhanced by the described method. GURZA also scored good results at the European championship in Tipaza – Alexander ranked 22nd as individual. As of today tenths of GURZA project guns found their owners. Both our natives and Russian, USA, Azerbaijanian, Italians, Canadian and Spanish people are among them.