mongooz
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Legal if you have a NFA stamp.
Look into a trust for max flexibility but no matter how you do it, buy the time you thread your 'host' or get new ones, go through the process & buy your suppressor, you're going elbow deep into your wallet. You can get a trust going to as low as $99
according to the ruger site, several of their pistols & rifles are ALREADY threaded for the suppressor and besides filling out Form 4 and a check for 200 all you have to do then is wait for the ATF approval, which they say can take a couple months. and the supporessor retails for 449, so real price should be around 300 (maybe).