September 7, 2018:
Since 2015 a Chinese firm (Norinco) has been offering for export the AH4 155mm towed howitzer. This weapon was basically a copy of the older British M777, but can be lighter and always cheaper. AH4 was designed to use all the same Western ammo the M777 does. There is a lighter (3.4 ton combat weight) AHS4 “mountain gun” version for moving around in rough terrain. The AH4, at 4.5 tons when combat ready, is only 3.3 tons for the weapon itself, is too heavy for that.
China also offers a GP6 laser guided shell that has a range of 25 kilometers and requires someone near the target (on the ground or in the air) to aim a laser at the target so the shell can home in on the reflected laser light. The U.S. developed this sort of thing in the 1980s (Copperhead) and found there was little demand for it on the battlefield. But other nations have fewer guided weapons available and China sells a lot of GP6 shells.
The AH4 has a longer barrel, which helps a bit with range and accuracy. The M777 has a 155mm/32 barrel. That means the barrel length is 32 times 155mm or 5.1 meters (16.7 feet) long. The AH4 has a 155mm/39 barrel that is six meters (19.5 feet) long. Normal AH4 range is 25 kilometers but with rocket-assisted rounds it is 40 kilometers.
The M777 has proved more useful, especially when using the GPS guided Excalibur or M1156 (ATK fuze) shells. The M777 is also very much combat proven. For example, a U.S. Marine artillery battalion fired 35,000 shells in five months while in Syria (June-October 2017) supporting Kurdish forces that captured the ISIL (Islamic State in Iraq and the Levant) capital city of Raqqa. The individual marine 155mm howitzers also fired more rounds per gun and fired the largest number of GPS guided rounds per gun in one campaign. Moreover, there were never more than six of the marine 155mm howitzers in action at any one time. The marines rotated artillery batteries in and out of Syria to allow for maintenance on the guns and rest for the crews. Thus each of the marine 155mm guns averaged 39 155mm rounds a day. But the marine 155mm howitzers fired over a hundred rounds on some days and only a few on others, usually on days they were changing position to keep up with the Syrian rebels. The marines fired a lot of M1156 GPS guided shells and often did so at extreme ranges.
The M777 has also been used in Afghanistan and that combat record has made it difficult for China to obtain export orders for the AH4. There have been two export customers, both in the Middle East. Kuwait said it evaluated the M777 and the AH4 before choosing the Chinese howitzer. Details of the evaluation were not revealed but it may have come down to price and diplomacy (buying Chinese weapons is considered a friendly gesture towards China.)
China is increasingly eager to compete with the most popular Russian and Western weapons. China has already taken much of Russia’s traditional low-end market and is now moving on to the more complex, expensive and effective Western designs. China often uses stolen tech and the Russians never really had the clout to stop China from stealing tech. But the West is different and better able to strike back, at least in theory. The Chinese are putting that to the test.
BAE (a major British arms manufacturer) developed the M777 155mm towed howitzer, which entered service in 2005 and is now mainly manufactured in the United States because the U.S. Army and Marine Corps are major customers. The M777 is a lightweight (3.4 ton for just the gun, 4.2 tons combat ready) howitzer that currently costs from three to six million dollars each. The lightweight means the M777 can be moved slung under a helicopter and thus quickly moved to otherwise inaccessible areas. The M777 is the lightest 155mm towed howitzer ever fielded. M777 fire control is handled by a computerized system that allows faster response time and more accurate shooting. The M777 can use all current 155mm ammunition, including the Swedish/American GPS guided Excalibur shell or the even cheaper M1156, which is a large fuze containing the GPS and guidance system. The guided round cuts ammo use enormously because one guided round will often get the job done quicker and with less collateral damage that dozens of unguided rounds.
The Americans began replacing their 1980s vintage M198s with M777s in 2007. Until then the M198 was the standard towed 155mm howitzer for the United States and many NATO counties. M198s weighs eight tons and can fire conventional rounds as far as 22.4 kilometers. For rocket-assisted projectiles (RAP) the range is 30 kilometers. These unguided shells land anywhere within a 200 meter circle. That's at 25 kilometers range. Accuracy gets worse at longer ranges. It takes 12 minutes for the M198 to be ready to fire after the truck towing it stops. It can pack up and move again in about 4 minutes. Using GPS the M198 can be in position to fire in less than ten minutes and shift to another target in about 8 minutes.
So far the U.S. has ordered over a thousand M777s. The manufacturer has also received a contract to refurbish 33 M777s that returned from service in Afghanistan. This cost $91,000 per howitzer. The M777 is also used by Canada and Britain. The U.S. Army uses M777s in airborne and Stryker brigades. A five ton truck is used to tow the guns, but a special, 4.5 ton LWPM (Lightweight Prime Mover) is available to do that as well.
The 4.2 ton M777 is much lighter than the M198 it replaces mainly because it (like the AH4) makes extensive use of titanium, and new design techniques. It fires shells with a maximum range of 40 kilometers (using RAP, or rocket assisted projectile, ammo). A crew of five operates the gun, which can be ready to fire in under three minutes, and ready to move in under two minutes. The M777 is light enough to be moved (via a sling) by CH-53E and CH-47D helicopters. Its sustained rate of fire is two rounds a minute, with four rounds a minute for short periods. The AH4 uses a crew of seven and has similar ready times and rates of fire.