There is nothing ambiguous about the 25% accuracy increase figure of the ZPT-98 over 1,800 metres of the original 2A46M-1. It is plainly stated in both the original Chinese-language and the English-translations of the article on Tianren's Blog. As I stated in a previous post, if you have doubts about the figure, E-Mail Terry Lau himself, his link is provided near the end of the article.
Attentuation is the problem with the 125mm gun; perhaps it is from too powerful a a propellant charge, too fast burning propellant charge, or too short a barrel for the charge used - for that matter, the original 2A46M-1 had an insufficiently rigid barrel, which was corrected in later production batches. The derivatives of the 2A46M-1 seem to share this problem; both the 25% accuracy improvement of the ZPT-98 (which works out to 2,250 metres) on the 1,800 metres of the original 2A46M-1 and the 2,500 metres of the Ukrainian KA1/KBM1 accord with this.
Clearly, if a 125mm Soviet or derivative gun such as ZPT-98 on Type 99 MBT wants to reach the published 3,200 of German/US 120mm (or longer such as the 3 mile/4,800 metres range that M-1 A1 tanks of the US Army 24th Infantry Division [Mechanized] tanks engaged and destroyed Iraqi T-72 and T-55 tanks at as they headed north to the al-Hammar causeway west of Basra - see "The Generals' War" by Michael R. Gordon and LtGen. Bernard E. Trainor (USMC ret.); I have already cited this source in previous posts, and this source contains the references to the After Action Reports concerned, and once again, if you do not find these credible then PM Utelore on our forum and ask him - he was an M-1 tanker who fought in the 1991 Gulf War ), then tank gun launched ATGMs with 4,000 to 5,000 metres range are required. And that is just what 2A46M-1 and ZPT-98 use.
Here is another source about the 2A46M, which describes near the bottom on Page 135 the accurate range of the 125mm on the T-72; it is from the University of Military Intelligence, a private-think-tank that is connected with, and has direct access to, both the US Army Intelligence Center at Fort Huachuca, Arizona (USAIC) and its classified documents. To access the classified documents from the USAIC that the University of Military Intelligence has, you must have DoD security clearance. Here is an unclassified manual prepared by the University of Military Intelligence for the "Ariana Forces" formerly known as the US Army OPFOR at Fort Irwin, California, the National Training Center:
T-72 Main Battle Tank
The T-72 medium tank is similar in general appearance to the T-64. The T-72
has six large, die-cast, rubber-coated road wheels and three track return rollers.
It has a 14-tooth drive sprocket and a single-pin track with rubber-bushed pins.
The gunner's IR searchlight is mounted to the right of the main gun. The 12.7-
mm NSV anti-aircraft machine gun has a rotating mount, and there is no
provision for firing it from within the tank. There are normally only a few small
stowage boxes on the outside of the turret, and a single short snorkel is stowed
on the left side of the turret. The T-72 has a larger engine compartment than the
T-64, and the radiator grill is near the rear of the hull. The T-72 has greater
mobility than the T-62. The V-12 diesel engine has an output of 780 hp. This
engine appears to be remarkably smoke-free and smooth-running, having
eliminated the excessive vibration which was said to cause high crew fatigue in
the T-62. Although the engine is larger than that of the T-64, the heavier (41 mt)
T-72 is believed to have approximately the same road speed as the T-64. The T-
72B1 is powered by a multi-fuel V-12 piston air-cooled 840 hp engine that will run
on three fuels: Diesel, Benzene or Kerosene. Two 200-liter auxiliary fuel drums
can be fitted on the rear of the hull. The T-72 can be fitted with a snorkel for deep
fording, and takes about 20 minutes to prepare for amphibious use. The T-72
has better armor protection than the T-62, due to the use of layered armor and
other features discussed above under T-64 capabilities. The advanced passive
armor package of the T-72M and T-72M1 can sustain direct hits from the 105mm
gun equipped M1 Abrams at up to 2,000 meter range. The later T-72Ms and T-
72M1s are equipped with laser rangefinders ensuring high hit probabilities at
ranges of 2,000 meters and below. The turret has conventional cast armor with a
maximum thickness of 280-mm, the nose is about 80-mm thick and the glacis is
200-mm thick laminate armor. Besides the PAZ radiation detection system, the
To verify this, go to Google.com, type in Ariana Threat Guide in the search box, and the first result should be the threat guide itself. Click on it (and once it loads - it is 6.92 MB, so it's BIG) and go to near the bottom of Page 135. There you will find the specification for the accurate range of the T-72 main gun - 2,000m. It lists the accurate range of the 125mm gun on the T-72 as being 2,000m - not far off from 1,800m that Global Security quotes. Even 25% improvement over 2,000m amounts to the same 2,500m of the Ukrainian 125mm.
This is about the best UNCLASSIFIED material you are going to get about the REAL performance of the 2A46M-1. And it is upon this performance that the 25% increase in accuracy of the ZPT-98 is based, and it readily accords with the performance of a fellow 2A46M-1 derivative, the Ukrainian KA1/KBM1.