The Chinese marines have been seen testing a new version of the decades old 76mm dual-purpose auto-loading, radar guided naval gun. The marine version was mounted on a 10x10 wheeled armored vehicle. In 2016 a Chinese firm had offered a version mounted on a 6x6 truck. Small warships (corvettes and offshore patrol boats), the main users of this weapon, mount the gun in a 5-9 ton turret. The truck-mounted and marine version appear to be the lighter weight turret. The naval versions usually have 75-150 rounds of ammo available. Each of these shells weighs 12.4 kg (23.4 pounds) so the weight of ammo alone is one to two tons for the vehicle-mounted versions. On ships, these guns are water cooled (using sea water) and even then they can only fire about 25 rounds before having to halt a few minutes to cool off. The gun has an effective (aimed) range of 10 kilometers and will travel up to 15 kilometers. The truck-mounted CJ26 had two hydraulic jacks in the rear that must be deployed to stabilize the vehicle before firing. The marine version does not need that as it appears to be much heavier (over 20 tons) and has more wheels. The radar and fire control system adds several tons.
The naval version of this gun has an interesting history. Designed for giving small warships effective anti-ship and anti-aircraft capability the first version of this design was introduced in the 1960s (by Italian firm OTO Melara) while the high RPM (rounds per minute) version showed up in the 1980s. The Russian basic version was first available in the 1970s and was sold to the Chinese who created their own version as the PJ26.
The Chinese paid more attention to OTO Melara developments because this Italian original was steadily updated so that by the 1990s it was effective against anti-ship missiles. What made this possible was the AHEAD shell which could be programmed by the fire control system while in the gun to detonate at a specific distance from the gun and produce a cone of tungsten (heavy metal) projectiles that acted like a shotgun shell that did serious damage to missiles or aircraft. AHEAD shells came in various calibers (30mm-76mm) and the Chinese/Russian version could reliably destroy and incoming missile (like the Harpoon) with under 25 rounds fired at 120 RPM (two per second). The PJ26 can fire single rounds at surface targets as quickly or slowly as desired. Smaller caliber versions (30-40mm) used as anti-aircraft or IFV (Infantry Fighting Vehicle) weapons could disable a tank with AHEAD ammo by shredding all external sensors and fire control system components. The tank crew would survive but they would be unable to use their main gun because the fire control system was destroyed. Against aircraft, the effects are worse because of such shredding damages jets and helicopters to the point where they can no longer fly.
It is unclear exactly what the Chinese marines intend their 10x10 vehicle version to do. Only pictures of this vehicle (painted in distinctive Chinese marines camouflage colors) have been seen. But the capabilities of the PJ26 are well known and this weapon can fire HE (high explosive) rounds and be useful for supporting a marine beach landing or ground operations in general. The 10x110 76mm weapon is not really a front line system since the fire control radar behind the turret can easily be damaged. The truck-mounted version uses a radar on a separate vehicle but is not as well armored or mobile as the 10x10 marines version.
The Chinese probably don’t know exactly what they want to do with these new land-based naval guns. But the Chinese often experiment via commercial firms that will develop new systems like this with their own money in hopes of getting a contract from the Chinese military which would then lead to export sales as well. This works often enough to keep Chinese manufacturers doing it.