I have Stevens 200 that was originally a .223, converted it to a .338 federal with a McGowan barrel. I changed out the magazine box, follower, bolt head and front baffle, using the ejector and extractor from the original .223 bolt head. I installed the barrel, set the headspace so that the bolt closes on the 1.630 GO gauge, but will not close on the 1.634 NO GO gauge, bolt handle will rotate slightly but not close down. When I try and chamber a round the bolt will not close, seems like the case will not slip under the extractor. I removed the extractor from the bolt and it chambers a round just fine. My question is, are there different extractors for the 223 bolt head and 308 sized bolt head? Any advice in appreciated!