Tanks' problems

I am playing with the vehicle addition pack and Tanks and other vehicles mod.

Tanks are friggin’ awesome. I just found a light tank while driving around with my mobile gun sistem, and it’s huge. Can’t wait to see the other one. (I know there is a third one besides the Mobile Gun Sistem and the Light Tank). Anyway, before this, I found a Chicken Walker. From the description, I presume it’s pretty big. I got frightened, and decided it’s better using too much fire power than not enough. So I ran inside my Mobile Gun Sistem and shooted with the 50. cal. I had more than 200 rounds so I can go full auto with no worries. I was at 13 tiles of distance, shooting with a heavy machine gun attached to a military vehicle, my character has 16 strenght ( which improves recoil management) and 14 dexterity and perception, 11 rifles and 8 markmanship, plus targeting sistem CBM. I shooted 25 times. I hit once. See the problem?
I think it’s probably because of the recoil. I could barely understand it if I was hand operating the Browning 50.cal, but it was welded to a 3 tons vehicle. It shouldn’t kick like that. Also, when shooting a mounted weapon cases fly all over the place and if you attach a brass catcher to a weapon the game won’t allow you to weld it to a vehicle.

Second (minor problem). I see the light tank weights little more than 10 tons. Ok, it’s ‘‘light’’, but even then, 10 tons are a little too light. My real problem with this is that after I salvaged all the treads from it, it lost like 40% of it’s weight. Is it realistic that nearly half of a tank weight is due to treads? And the main body is barely 6 tons?
To have some comparison: the modern USA battle tank, the M1 Abrams, weights 55 tons, while the PL-01, a polish light tank, weights 30 tons.
I would fix this my self, but I have no idea where to start or even how to program. I would suggest coding in things like '‘military frame’, or ‘‘military quarterpanel’’. Super heavy, super resistant, and maybe not craftable. But if craftable, extremely resource demanding.