I've been considering buying a 223 bolt head and opening it up to custom fit my Winchester brass. You would need to headspace your barrel after changing the bolt head. I changed the extractor ball also and it didn't help. I ended up losing my ejector while I was fiddling with it one day and I shot it without it while I had a new one on order and I decided I liked it that way. But mine is a LPRB single shot.

Another thing you might try is a different brand of brass. My Winchester measures .465" at the rim and my buddies Nolser brass measures .470". It's also .004-005" larger ahead of the extractor grove and doesn't show a bulge after firing. This is a 22-250 rifle by the way.