Just last night I flew home from South Africa, through Dulles Airport. When my name was called, the Border Patrol lady asked me to place my gun case on the table and said the following, 'unlock your case, do not open it, step back from the table'. I did as instructed, she and a fellow officer opened the case, checked the serial number, the one guy yells to the head guy and says, 'you should come look at this rifle'. The head guy comes over, I say to him, 'go ahead and pick it up, see how light it is', the head guy does pick it up, says 'wow, what caliber?' I say, '308', it was at that moment the head guy sees the suppressor and says, 'wow, this thing suppressed is a sweet rig', 'looks like we're all good here'. So I shut the case, locked it up, and was walked to the exit.
When I first met the young Border Patrol lady, I handed her my 4457 and Tax Stamp for the suppressor. Not one question was asked about the suppressor.