We had another member have a similar problem with go and no/go gauges. You are correct the go gauge should be smaller and fit where the no/go might not. Need to ask are they from the same manufacturer? Maybe one has a larger bevel then the other.

Going out on a limb for the original problem singe fed rounds chamber, magazine fed do not. If the magazine cut off selector for feeding single rounds is not in the rifle it can really scar the rims when feeding from the magazine. Maybe the deformed rims do not chamber? If so get the selector or build a mock up out of a nail.