Where to Purchase
A silencer may only be purchased through a firearms dealer with a special BATFE Class III licensed Federal Firearm dealer. The buyer must be at least 21, eligible to purchase a handgun, and a U. S. citizen.
Paperwork and Approval
Prior to purchasing a silencer, two completed ATF FORM 4s, two completed ATF FORM 5330.20s, a fingerprint card, two passport-style photos, and a $200 transfer tax fee must be sent to the BATFE for approval. The specific silencer must be noted on the FORM 5330 by the silencer serial number.
The approval takes approximately six months.
Alterations
Any part intended for use as a silencer is considered a silencer by law. A completed silencer must be marked with a controlled serial number. The owner of a silencer may not legally have any spare parts for it. A silencer may not be altered in any way, including major repairs except by the manufacturer. Replacement of the outer shell is considered the manufacturing of a new silencer.
Destruction
A silencer may only be removed from the provisions of the ATF by its total destruction such as being crushed flat or cut into multiple small pieces.
Legal States
States that do allow residents to own a silencer with the federal government approval are AR, AZ, CO, MD, FL, GA, NE, ID, KY, LA, UT, CT, ME, NV, WY, MS, OH, NH, OR, IN, NM, MT, NC, OK, PA, WI, SC, AK, SD, WA, TX, VA, AL and TN. Some cities within these states may have a municipal ban on silencers so consult your local Class III firearms dealer to ensure no law is broken by purchasing or owning one.