Hi , sorry I have not replied sooner .My mark 1 is now in cal .17 MachIV ..The extractor caused a lot of headaches and was a lot of work , the main problem I encountered was the fact that the extractor is pressed hard against the breech face when the action is closed and against the bolt face when the action is open ,this prevents the extrator arm (the bit that fits in the cut on the cartridge head ) from moving side ways, as it must do to extract the cartridge .. I made a completely new extractor which allows the bit that does the work to move around the rim and into the groove without contacting either the breech face or the bolt , the concept was easy putting it into practice was a challenge ..Detailing what is entailed here , would I think, take more space and time than would be allowed but I can be contacted at lefty1@paradise.net.nz
.... Rob