We should have barrel change for mg42 and mg34, as well as other weapons that had a quick barrel change as a key part of their inherent design and function animated. It would be fine even if it takes as long as current cooldown for all machineguns, if it had a very realistic animation involving taking out a pouch which has the barrels and putting it away.
I want to see the g41 reload fixed first before an implementation like the aforementioned, however.
I want this animation too, but…
… I want the lmg to overheat after longer than about just 5 seconds or so.
Imagine switching barrels after every 5 seconds… 
I think that all mgs need less aggressive overheat so that barrel change can be relevant in that aspect too
If we would go with this MG rework than it would be really good
it would be better for built HMGs, at least. a more asymmetrical balance in AA and HMGs would be fun. As for LMGs, it could remain the same or have overheat apply to belt fed ones like the 30cal or other 100 round guns to be added