If you have a lathe and can get a chambering reamer I would do it my self. I also would make up the extractor/ejectors and cut them at the same time as the chamber is cut. If you try to cut the extractor latter you stand the chance, and a good one of the reamer enlarging the chamber. If this happens at best your brass will have a short life and be hard o resize and in the worst case you will need to get new barrels. Dave Manson will have the chambering reamer, probably in stock and his reamers are great. If you do not find his # let me know and I will give it to you but it is in my shop and I am in my house. I think the business name is LOON LAKE PERSISION TOOL. You will find brass, loading dies, and bullets at Huntingtons and they will be on the shelf. If you get stuck give me a call any time.