Free: Contests & Raffles.
Nope you need a blank adapter to hold enough pressure to cycle the action. Side note: those are highly corrosive and will dirty up an action like you can't believe.
Yes, if you are firing on an AR platform (or any other semi-auto) you need a blank adaptor. They might work in a bolt action though .Woodchuck is right on about the carbon buildup though. I still have nighmares about cleaning M-16s after blank firing missions....
Don't tell the armor that we also put them in the solvent tank, or that we bead blasted the bolt carrier and chamber of the M2.....
on a side note a blank and a cleaning rod will take out small game like a squirrel at close range