Not to hi jack Mr. Soviet, But I have a question about this:
"Basically a can will work with anything its rated to and lesser calibers. Instead of the .556 can, a dedicated 22lr can would be better."...
Can you use a 22lr can on .556?
Yes you can use .22 in a 5.56 can, the issue is .22 is very very dirty. There are very few user serviceable 5.56 cans on the market, this is why it's not recommended to shoot .22 through a non serviceable 5.56 can, it will fill with lead QUICKLY. The other issue is the level of suppression using a 5.56 can for .22, a 5.56 can is not anywhere near as quiet as using a dedicated .22 can.