Get in touch with a dealer who may retail supressors. You make the purchase, fill out the form 4 and send it to ATF along with the $200 tax stamp fee. Once approved, typically 3 months, the form will come back to the dealer, he will contact you and you can pick up your supressor.
Or if you have a trust or LLC already you substitute that for the personal info and the wait goes down to a month or less.
This is as I understand it a the moment, I'm sure someone who knows the process in greater detail can give you better info. There are a multitude of threads available online in discussion forums such as this one. Some great links are:
http://www.quarterbore.net/forums/showthread.php?t=174
http://www.glocktalk.com/showthread....hreadid=199037
http://www.silencertests.com/legality.htm
http://www.gem-tech.com/legal.html
Copied from SoundTechSilencers: A private citizen may purchase a suppressor directly, BUT, in order to legally receive it he or she will have to work through a Class 3 dealer or Class 2 manufacturer in their state. You will transfer the suppressor to the local dealer through a form 3, approved by BATF, which takes a minimum of 30 days. Once the local dealer receives it, he may then transfer the weapon on a form 4 (which costs $200) to the individual. The dealer usually charges a minimum of $50 for the transfer, which usually takes a minimum of 90 days.
You can also look over at AR15.com and subgun.com for waaaay to much info on the subject. I'm setting up a trust as we speak to make the next transfer much smoother. My current SBR permit is taking way too long to come in.