Support Ammo Resupply Not Working!

There is a bug or design flaw that you can not resupply launchers grenades or other equipment from a support player without them throwing down their bag unless you are low on gun ammo or health only.  This is supposed to be fixed by the fact you can just run up and take the ammo from the oblivious support player instead of just spamming the "need ammo" request over and over just to be ignored.  As an engineer player, this affects game play very negatively.  I am trying to kill a tank with the support not giving me rpg ammo I need and I can not just take it unless I start mag dumping to a certain level before I can.  Please get this fixed!