I do not shoot a 22-47L or any 22 for that matter. However, necking down is a standard procedure no matter the cartridge(s).. Since you are going down quite some distance, from .264 to .224. You will need a few tools: 1.) neck turning implements; 2.) 2 / body dies, assuming they have them. OR you will have a major duty "mess" on your hands, 3.) F/L .22-47 Bushing die.
1.) Take your neck turning Die /Mandrel with a .264 expander mandrel and expand the necks. ****Assuming**** ( I hate using that term) assuming the 6.5 x 47 neck wall thickness is 14 thousandths, you will need to turn them down to AT LEAST 12 thousandths, of course depending on your reamer. But I would imagine 12 thousandths is necessary.
2.) Take the 6 x 47 BODY DIE and run the cases into that. This will create a perfect 6 a 47 case with the case mouth of about a 6 x 47 fired round.
3.) Now take the 22 x 47 BODY DIE and do the same as step #2. Now measure the neck wall thickness again. You will notice it has grown in thickness substantially. Now TRY and run the case as it now sits into a .22 expander mandrel. If it is a relatively tight fit, you can turn the necks down again to the proper thickness to make at least a 3 thousandths neck wall clearance. IF IT IS NOT a relatively tight fit, measure the outside diameter of the neck and take a bushing (try one with 1 thousandths smaller than the O.D. of the neck) if it is relatively tight, turn the necks down to the proper size. If it is still somewhat loose, which I don't think it will be, go down 1 thousandths more. Once you reach the proper fit for the 22 cal cutting mandrel, you will be ready for step #4.
4.) Turn the necks down to the proper neck wall thickness.
5.) Once this is done, anneal the brass..
6.) Now find out the proper bushing you will need, after the turning of the necks from step #4, for the neck tension you desire. I always try about a 1 thousandths neck tension.
7.) F/L size with your proper bushing..
8.) Prime
9.) Use a Q-Tip and swab the necks out with Imperial Dry Neck Lube
10.) Charge and seat the bullets..
After the first firing, you will have absolutely perfect brass.. This "procedure" should be used when necking down 2 steps or more. TRICK: Prior to neck turning the first time, while they are still at .264, take the OUTSIDE chamfer tool and knock off that edge and your cutter on your neck turning tool will glide onto the brass.