I think it would be cool if we could get separate durability counters for different weapon parts, but only what is deemed as vital for the gun to work (minus hand guards, grips, and stocks)
Thia would maks it so each part would have separate durability and different malfunctions, upper recievers could have misfires, problems ejecting casings, and jamming. Gas tubes/blocks could have a very small chance to explode (VERY SMALL CHANCE). Lower recievers could have problems accepting mags and would increase reloading times. I'm not sure yet for barrels. And supressors could also get durability counters and malfunctions like baffle strikes or increase in sounds due to wear.
They could also add later, heavier and lighter barrels
Heavy barrels would have bonuses like accuracy, less recoil, and higher durability. But they would have less ergo.
The mid weight barrels would be the default barrels we have now.
Lighter barrels could have bonuses like higher ergo and faster ADS, but would have less durability, higher recoil, and less durability.
TL:DR- Each vital weapon part should get a durability counter and new malfunctions/failures