Overview
125mm D-81 line of guns utilizes two-part ammunition that consists of a propelant charge and different projectile parts (APFSDS projectiles have an incremental charge for greater energy).
The propellant case is of a semi-combustible type, consisting of a fully combustible pyroxylin-cellulose, TNT-impregnated tube set in a rear stub made of BV-11 steel, that also incorporates the GUV-7 electric primer.
The gunpowder is of high-nitrogen pyroxylin straw type.
The charges are produced by the State Scientific Research Institute of Chemical Products in Kazan.
Propellant charges
Common properties:
| Charge weight | 9400g |
| Stub weight | 3400g |
| Propellant weight | 5000g |
| Charge length | 408mm |
| Stub length | 140mm |
| Flange diameter | 172mm |
| Primer | GUV-7, electric/percussion |
Composition: 15/1tr V/A (1.5mm burning arch high-nitrogen pyroxylin stick gunpowder) + 12/7 V/A (1.2mm burning arch 7-channel high-nitrogen pyroxylin stick gunpowder) + VTKh-20 (flame-supressing gunpowder) + DRP-3 initiating gunpowder.
15/1tr V/A completely replaced with improved 12/7 V/A.
New high-energy propellant that allows to increase APFSDS muzzle energy by 5% over the previous charge models.
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| 4Zh-40 charge cutaway and markings: 1 - charge designation; 2 - artillery system designation (caliber and model); 3 - gunpowder composition, batch, year, and gunpowder factory designation; 4 - batch, year, and charge factory designation; 5 - batch, year, and arsenal designation (if present) |
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| 4Zh-52 charge cutaway. Note that single-channel grains were erroneously used in model construction, whereas 4Zh-52 in fact utilizes the 7-channel propellant. |
