There's your answer nee... and that's why they don't need a rebuy option because they'll be dead.
All right listen up here, back in my day, Guards' players
loved when their PTRSes dropped. They had to pick them up to get them again and couldn't rebuy them, but the Mosin replacing it would actually do something against infantry versus the PTRS doing barely anything!
But really, because of them having 4 heavy weapons when fully-upgraded, there's the possibility of a weapon dropping (10% now, I think) once they go down to three men, so whenever that happens, their PTRSes or DP-28s can be dropped. So fighting down to the last man usually won't drop even one weapon, but it can.