I have a green over white tip XM276 dim tracer, which was apparently a production error where the white should have been pink? After looking up some info I see that a LC 70 and LC 92 headstamp are known in this type, but mine is an LC 93. Is this a known thing, or are there other headstamps known with this white instead of pink error. Is that in fact a rare error? 7.62 NATO is not my thing.