In game the accessories such as Muzzle brake, bore evacuator, heat shield and counter weights are part of the Barrle hitbox, meaning if and by any rounds the muzzle brake or other part is hit and damaged, the whole barrle recives the damage, this is however not realistic, as the muzzle brake nor the other parts are a critical part of the barrle and the barrle will still works after those are hit and pierced.
I would like to suggest, that ONLY the barrle itself is part of the Hitbox to damage it, removing the Muzzle brakes, Bore evacuators, Weights, Heatshrouts and more. As they are not critical to the barrle and shouldnt hinder the barrle when hit.
This was however denied as a suggestion reason “It is a Hitbox issue” as such i would late perhaps put it forward as a Bug report.
More Details: (Click to show each)
Muzzle Brakes:
A muzzle brake redirects the gasses and relives the recoil cylinders with different effectiveness from gun to gun, but is also not needed in that rolle by all guns and sometimes just acts to redirects gasses to improve visibility such as on the Jagdpanzer IV and StuH 42, where they were later simple removed as tests showed it was not needed as the mount was sturdy enove to fire without it.
Another example is that even the Pz IV/70 (V) and (A) dont have muzzle brakes like most Panthers have.
And effectively is a mere Aim target in game.
In game the muzzle brake should be a seperat part of “Gun Steel” and not part of the Barrle nor of the Barrle module.
As when damaged or pierced they most often will still work as inteded, if not simply stopping to work or be less effective.
Bore Evacuators:
Bore evacuators only came to be after WW2, when guns became bigger and crew ergonomics could be fully taken into considderation in tank and tank gun development as there was no more a worldy threat (not taking the COLD war nor vietnam war into considderation)
The Bore evacuator is also not critical as it just is a sleeve on the barrle with small holes on the inside creating a vacume after the round passes by, sucking in the gasses and smoke and prohibiting it from going back into the fighting compartment when the breech openes, however tanks often (except some Oscillating french turrets) have an overpressure system, by which gasses from the outside (in case of hole or the breech) cant come in as protection from poison gas and such. Which also protects against the propellant gasses.
As such when it is hit, it may not even stop working and if it would, the overpressure system of the tank would take over the work, while overall it isnt even critical to the work of the gun.
Just like Heat sleeves which only even out the heat of a barrle, so that it doesnt morph if it is hot and it rains, or one side is under longer sun heat, but not critical.
Others:
Last but not least (if i didnt forget any other barrle accessories)
Counter weights on barrles.
They most often come on tanks which multiple armarment, or which recived a new or different armarment, as guns are ballanced for the elevation gear for it to either work propperly or be easy to use, a out of ballance gun would (it it isnt too big) be simply require more strength of the hand elevation or electric/hydraulic traverse (which would be even less affected)
Some examples as such is rather rare would be the M109G as it has a shorter barrle and thus has a barrle weight. The M10 Archilles, it has a longer barrle and heavyer bigger breech, requiring a barrle weight. Some other times this is integrated into the design of the Muzzle brake. The M3 Lee with the M2 gun also has one, required for the Stab to work as the barrle is shorter and lighter compared to the intended M3 gun.
As such if a round goes through them they dont disapprear they only loose some weight and still continue to serve their purpose, however generally they are not critical for the work of the gun.
Often with such tanks have also different counterweights on the back of the turret such as the M10 and T26E1-1 these count as mere Construction steel and dont change anything when shot off, so why should the barrle weight destroy the barrle.
If i forgot any other accessories feel free to comment.
Source:
Flicker
Bundesarchiv
Private collection
Tank Historia