Sounds like the frame is worn where the bolt passes through, and/or the firing pin channel. If so, a new bolt and firing pin will not help. Remove the bolt and firing pin and check the firing pin channel to determine if it is elongated or egg shaped. It really doesn't take much to throw off the tolerances, when combined with all the other wear on related parts. A good gunsmith MIGHT be able to weld up and recut those areas, but it is a very difficult restoration process, and if not done correctly.....well, you don't want to go there.
One thing that MIGHT help is to install a much light hammer spring. Sometimes that reduction will provide some improved function.
Good luck.