Hello!
Like Ed wrote, resin CAN be bent relly well. You just have to heat it a little, boiling water is the best way. This way you can make tank tracks really conveniently, many resin kits do it this way: They give you a couple of straight runs and you heat them and bend them, you can even make a nice sag that is then set.
For your application it would be important to have the place prepared where the ammo belt goes, to act as a jig. After you heat your ammo belt you have a short moment (seconds) wher you can bend it, as it is really soft. You do the bending best by pressing the belt into the place it is supposed to go. You don't really have to cool it with water, light parts cool down on themselves quickly enough.
Hope it helps, have a nice day
Paweł