the heat on the base of the studs should have allowed the swedge to fold in around the stud, provided you used enough [dull red would do it i would think]. the problem of bending was caused by the fact you used no support on the inside of the drum/hub assembly. you may want to check the other hub/drum assembly if you re-install the studs to make sure it isn't slightly bent. when re-installing the new studs, make sure to support the flat portion of the hub face to insure it doesn't get bent in the process. i have seen[and done] that myself. if successful, you may want to have a slight cut preformed on the drum to make sure it stayed round in the process. let us know how you make out.