Paul Clark has written an article where he notes that if you use of most Title II firearms during a crime of violence or drug trafficking you are subject to a 30 year mandatory minimum sentence. It appears that the 30 year sentence applies to the possession and its use is not required. Note this applies even if you are legally in possession of the silencer by ownership in a NFA Trust, corporation, LLC, or individual ownership.
While the data appears to show that the use of a silencer or most other Title II firearms in a crime is a rare occurrence, individuals might take this into consideration when using silencers on personal firearms when there is a chance that they might be charged with a crime of violence, such as defending yourself.
While many states have stand your ground statutes or castle doctrines, its possible that overzealous self-defense can lead to criminal charges. If the charges are in the federal court, you could be looking at enhanced penalties like those described in 18. U.S.C. Section 924(c)(1).