My advice would be to have a dedicated 22lr can and get a seperate can for 556.
For 22lr cans you cannot go wrong with XRT. His kits are the end all be all for 22lr form 1 cans. I mention his work to everyone because there really isn't a need to go with any other supplier for rimfire cans. His parta are just that nice and they're really cheap for what you're getting. I think my 5.9" set up was around $150.
Go with a 5.9 tube and shove anywhere from 9-11 baffles in there and not look back. I'd start there and if you have fun putting that together you can travel down the form 1 rabbit hole.
His website is:
www.xrttactical.comIf you go this route and need some help with what to buy people here can contribute some good recipes.
The only reason I'd use a D Cell maglite is for an IDF clone.