If Pakistan is manufacturing something is most probably Ukrainian KBA3 or some older 2A46M copies... or even Chinese ZPT-98 also 2A46M copy.
Sir why you think we need to copy others Gun?
as far as i know gun is nt a alien tech.
anyway some official info regarding the HMC
manufactured Gun.
A project to manufacture the first Pakistani tank
gun barrel was begun by Pakistan's Strategic
Plans Division (SPD), which was set up in 2000. In
April 2011, it was reported that the first Pakistani-
produced tank gun barrel was ready to be
delivered to HIT for installation on the Al-Khalid and Al-Zarrar. Previously, HIT imported 125 mm gun barrel blanks from France for the two tanks
which would then be machined in Pakistan by
HIT. The first Pakistani gun barrel blank was
produced at Heavy Mechanical Complex (HMC) in a
joint project involving HIT, People's Steel Mills
Limited (PSML) and other defence-related organizations. The specialist grade steel was
produced at PSML and the resulting steel block
was passed on to HMC. HMC then pressed the
block to a length of 5 metres and square cross-
section, before forging it into a 125 mm
smoothbore barrel. The barrel was then heat treated several times in facilities such as a large
vertical furnace. The process took 2–3 months
and was watched by experts from other defence-
related organisations. The barrel was to be
capable of firing at 4 rounds per minute as well as
for compatibility with the autoloader and its 24 round magazine. According to a HIT official, a
joint team proved to the Pakistan Army that strict standards would be met before the army
approved production of a first batch of 50 gun
barrels by HMC. The Pakistani gun barrels would
likely be installed on upgraded versions of the Al-
Khalid which are under development by HIT. A
Rs200 million PKR contract has been finalised by HIT for the first 50 barrel batch, which is slightly
lower than the barrels imported from France. After
production of this first batch of tank gun barrels,
HIT is planning to explore manufacture of artillery guns