I regularly get emails from people asking me to tell them how to do something illegal. Often these people phrase the questions they ask in such a way as to trick me into telling them how to break the law. Today someone told me his friends and him were having a debate whether or not a .300 BLK round could be suppressed with a oil filter, and if so, which would be the best brand to use … I was not born yesterday. I am not going to tell you what brand of oil filter to use to illegally suppress a rifle.

For those of you who are not aware, a couple of years ago the concept of using a automobile oil filter as a suppressor spread across the internet like wildfire. One company began making cheap $70 adapters that were legally registered as suppressors. Other people committed felonies by using simple cheap thread adapters to make illegal suppressors. These adapters are now sold as “Solvent Traps” or “Solvent Catchers” … like you cannot use any random metal or glass container (or just a dirty rag) to catch solvents poured down a barrel.

I thought the oil filter craze was long dead and retailers had stopped selling them. After achieving the above mentioned email, I did a Google and found the trade in them is alive and well. One eBay merchant is selling around 1,000 simple thread adapters each year for just $9 (including shipping!). He also sells a range of adapters for popular unthreaded rimfire rifles. They are sold as “Solvent Traps”.

Using these, or being caught with an adapter, a threaded rifle and a oil filter could land you in Federal prison. In 2012 a man was sentenced to 2 years in a Federal penitentiary for illegal possession of a homemade suppressor.

Yes, the law is ludicrous, I am not defending the law. That a simple thread adapter can be illegal to use on a rifle, but a muffler can be used on a car makes no sense. But regardless, spending a couple of years in prison and never being able to own or buy guns and ammunition again, is far too steep a penalty to justify the risk. Suppressors are fun, but they are not that much fun. Trust me, I own many suppressors. Save up and buy one legally. In the day of camera phones, all it takes is for one friend or neighbor to photograph/video you using or making an illegal suppressor and you can then kiss all your guns, and your freedom, goodbye.