When using BIS_fnc_compatibleMagazines with the local variable _muzzle, _muzzle is being changed from a muzzle (string) to a config entry:
systemChat str ["CHECK 1",_muzzle]; //["CHECK 1","LMG_coax"] _compatMags = [_muzzle] call BIS_fnc_compatibleMagazines; systemChat str ["CHECK 2",_muzzle]; //["CHECK 2",bin\config.bin/CfgWeapons/LMG_coax]
This doesn't do it with a differently named variable, such as _muz.