can I get one suppressor that will do both? obviously I wont put a 22 can on the AR, but I have an AR that I would like to suppress. Can I swap it over to my 22?

http://www.ar15.com/forums/topic.html?b=6&f=20&t=258731

Perhaps we can tack a thread about this topic up at the top.

This question is probably asked once a week AT LEAST.  I know I asked it, too, when I first came here.

Just a suggestion.

Short answer is yes, you can get one supressor for use on both a 5.56 and 22lr.  That said, it's not recommended.  Here's why.  A 22 can will not stand up to the pressure of a 5.56 round, so you're going to have to purchase a 5.56 can.  Typically, these cans are much larger and heavier than a 22 can.  You don't want a 1 lb or more can hanging off the end of your little P22 do you?  Also, 22lr is a dirty round.  Why shoot crap through your 5.56 can and fill it up with carbon and lead.

You're much better off having a dedicated can for each of those calibers.  I'd start out with a 22 silencer.  It's cheaper to shoot, cheaper to buy, and as close as you'll get to Hollywood quiet.

Buy a dedicated .22. Then buy a 5.56.

+1

That pretty well sums it up.  Believe me, we've all gone through it.  You have limited funds, and you want to get something that gives you maximum flexibility.  A full-sized .223 can isn't all that bad on the end of a short .22 rifle, but it's terribly cumbersome on a pistol.  

Also, a .223 can is optimized for use with a high-pressured round, and a dedicated can is going to be optimized for the lower pressure of a rimfire.  The smaller rimfire can will often sound better with .22 even though the centerfire can is larger.

I ended up buying a .223 can that is the same size as most .22LR cans.  Being that small, it is only rated for semi-auto .223 fire.  Looking back, I should have just gone with a dedicated .22 can and bought a centerfire can later on.  As noted, the can is not as quiet as a dedicated rimfire can.  Also, it is still kind of loud on a 16" AR15.  Any more, I only use that can for full-auto .22 (for which it is rated) and on a long-barreled single-shot .223.  

I've since bought another can for .22LR, and I'm waiting on a full-sized .223 can.  

The other can gets 95% .22LR through it anyway.