Q: Will this extractor work with 12.7x42?
A: Yes, the extractor will work with the 12.7x42
Q: I have an enlarged round lug bolt for 6.5. any idea who made it. It came with a black fluted barrel and this bolt
A: Maybe check with AR-15 Performance, it may be one of their bolts?
Q: Is this for the "type 2" bolt with .135 to .136 bolt face depth? I recently bought a bolt that had the wrong extractor installed and it will not extract shells at all.
A: Yes this 6.5 Grendel Extractor is for 6.5 bolt assemblies with a .136" bolt face recess or as you stated what the AR-15 community calls Type 2 bolt.
Q: Is the .223-.5.56 extractor the same as 6.5 Grendel extractor?
A: No they are not. The call out specs are different for 5.56/223 and 6.5 Grendel extractors