SAAMI is a voluntary standard US companies use to establish headspace dimensions. CIP is the Euro equivalent. Commie Milspec is not required to adhere to either, which is why ya get these issues. Subtle differences in shoulder angle and such. As long as live ammo feeds and extracts, you have enough headspace, and the gauges not closing indicate you don't have too much. Good to go.
If your gauge is actually chipped, I would lightly hit the chipped area with a Dremel cutoff wheel and chamfer the edge, at that spot only, to ensure no raised metal is causing a bad reading. Most gauges I have seen do have a slot machined in them to clear the ejector, could that be the "chip"?