Hello All. I have been chewing over the idea of making a chamber adaptor for my Alexander Henry .577-450 s.s. rifle to shoot black powder .45-70. making another extractor will be the easy part. I would like to here from anyone that has been down that road as where i live Bruce Bertram wants A$6 per case for .577-450. I am sure i saw an article on an adaptor for the Martini Henry but cant remember where. Any info is most welcome. Regards .45-90 Down Under