The first production smoothbore gun manufactured by the Motovilikha Plants Corporation was the 115 mm 2A20 installed in the T-62 MBT.

This was followed by the 125 mm 2A26 and 2A26M2 which were installed in the T-64 MBT which was only produced for the Russian Army.

Further development resulted in the 125 mm 2A46 series of smoothbore tank guns which are also referred to as the D-81TM. This family includes the 2A46M and 2A46M1, all of which fire the same natures of separate loading ammunition. It has no muzzle brake but has a bore evacuator and is fed by an automatic loader using a 24-round carousel system. A light alloy thermal sleeve is usually fitted. Maximum effective target ranges are around 4,000 m using APFSDS and HEAT rounds and 5,000 m using HE fragmentation rounds.

In addition to firing a complete family of separate loading ammunition (projectile and charge), some 2A46 smoothbore gun installations have a different fire-control system that also allows them to fire a 125 mm laser-guided anti-tank projectile, details of which are given in the Vehicle-mounted anti-tank guided weapons section.

As well as the installation of this 125 mm weapon in the T-72 (2A46), T-80 (2A46M1) (T-84, built in Ukraine) and T-90 (2A46M1) MBTs, a modified version of this ordnance is used in the 125 mm 2A45M towed antitank gun.

The 125 mm 2A45M is the replacement for the older 100 mm T-12/MT-12 towed anti-tank gun which entered service as far back as 1955. As far as it is known the 125 mm 2A45M anti-tank gun remains at the prototype stage.

The main difference in the late production 2A46M and 2A46M1 is that two cylinders of the recoil brake are installed symetric about the barrel, weaked braked primary recoil, stronger barrel, bead on barrel for correction sights without heat beding and finally the barrel can be quickly detached.

In May 1989 Iraq showed a Type 69 MBT that had had its 100 mm gun replaced by the complete gun and automatic loading system of the T-72M1 MBT, but as far as is known this never entered service with the Iraqi Army and was not encountered during Operation Desert Storm, the recapture of Kuwait in 1991.

In production. Installed in T-72, T-80 and T-90 MBTs and in a modified form serves as the 2A45M towed anti-tank gun. The earlier T-64 MBT has the 125 mm 2A26 smoothbore gun which has a vertical ammunition stowage whereas the 2A46 gun installed in the T-72, T-80 and T-90 MBTs has a horizontal feed system. The 125 mm 2A46 is also installed in the Polish PT-91, T-84 (Ukraine) and former Yugoslav M-84 MBTs.