"Normal for Eastern Block Tanks!
Portuguese Leo2A6 firing at its side, 120/55 gun
Keep the volume low for this!
(Dont try to translate)
The VT-4 probably had that slightly and somewhat higher recoil oscillation in that particular video due to a variety of factors some of which are illustrated below:
1.
Ground damping: How much energy the terrain can absorb and dissipate without hopefully transferring it back to the tank.
2
. Elastodynamic properties of the ground: how much energy is absorbed and then returned to the tank due to the elasticity of ground surface the tank was moving on. If ground surface itself displaces and springs backup without much plastic (i.e. permanent) deformation, it will transfer some of energy back to the tank causing it to further oscillate as it moves adding in to later recoil when firing. Yes, even the seemingly rigid ground has some springle like recoil of its own when pushed down really heard, capable of tranfering energy from ground to the tank. Nothing is perfectly rigid.
3. Tank state: The velocity of and acceleration of the tank while firing has a profound impact on recoil oscillation frequency and amplitude (and its decay). Plan English: how fast tank recoils and how far, is affected by its its overall motion (in rigorous engineering terms rigid mode oscillations are function of vehicle state among other things).
4. Energy transferred to the tank components (due to their elasticity such as tank suspension system and other structures having elastic and damping characteristics of their own): This too will create unique recoil profile. Furthermore as tank moves on uneven ground, these elastic components carry a lot of energy in them which combined with firing recoil may give tank a far bigger oscillation than when moving smoothly and slowly on an even ground (where they carry less energy).
5. Current weight and weight distribution (due to component arrangements, ammunition, fuel, etc.) and overall weight of the tank: how much a tank weighs and how that weight is distributed will also create a unique recoil profile.
6. Position and orientation of turret, type of round fired
and so on.
The point is some characteristics are chosen for a given tank (e.g. suspension optimized for certain "terrain-tank interactions") and some depend on terrain upon which the tank is moving on. A tank on certain terrain types for which it was optimized may behave dramatically differently than on a different terrain. One usually finds compromise and that depends on customer needs and personal preferences of the designers.
So we can't compare one tank moving and firing in a different environment with one in totally different one. Even when in the same environment a tank may differ in behavior depending on what they were trying to optimize or aiming for when it was designed. For example some may behave differently (have different dynamic characteristics) because they are supposed to experience less wear and tear and to increase maintenance time interval. The list goes on.
VT-4 can't be therefore be compared with another tank based on some videos of other tanks. All tanks are different and optimized based on different preferences and requirements, giving them different recoil profiles among other things.
I know you were NOT comparing the tanks, just merely pointing out some similarity but still I felt the need to say few things anyway.
