[VUPDblue]

Only a few companies make suppressors

Not true. There are lots of different suppressor manufacturers, dozens and dozens!

The above advice from other posters is correct in stating that it is very expensive to own one. The goverment will put a register tax of several hundred dollars on this item.

Only semi-true. If the $200 tax is 'very expensive' to you then you would be correct. Otherwise, that is the only cost above and beyond that of the can itself.

Then there is the price for one to put on the firearm of your choice.Threading the barrel or geting a clamp on version from a reputable source will set you back thousands of dollars. Machining needs to take place before the firearm will take the " silencer".

Not true. I have had several of my AR barrels cut down, re-crowned and threaded to match the thread pitch of a couple different cans. It costs me $65 every time I need a 'thread job' done.

All silencers need heavy duty maintenance. Cleaning and lubing with the right materials to keep the can quiet and up and running. Baffles need cleaned frequently. These items all have a limit use as to the number of rounds one can fire through it before wearing it out completely

Not true. Aluminum or Stainless cans need only be soaked in solvent (WD40 or mineral spirits & ATF) for a day or so, and they come out squeaky clean. The recommended artificial environments in most cans is water or light oil. Gemtech recommends I clean my .22 can after 1,000 rounds and that it will last indefinitely if maintained as listed above.

Now for the sticky part. If one has a criminal record or is a felon or uses a silencer for illegal activity,that person is going away for a long time. The BATFE can pop in at anytime and check up on your registration and legality of said suppressor.

True and not true. If you are a convicted felon you WILL be denied on your form4 application. Simple criminal records do not automatically mean denial of your Form4, I have seen some issued to people with minor misdemeanor offenses (read: Public Intox, patronizing a public nuisance, etc) the only way to find out for sure is to submit your ap and see what happens. Only once has a crime been committed with a registered Class 3 weapon and that was a LONG time ago, and by a LEO! {If someone commits crime #2, I will personally hunt him/her down and beat them with a wet noodle!} BATFE cannot conduct warrantless searches of your person, vehicle or home simply because you have a registered suppressor. They can, however, ask you to produce your Form4 if they SEE you with the can, but then so can any other LEO.
The best source of maintenance info on silencers is directly from the manufacturers. You can email them and request a copy of their owners manual, or ask a dealer. I recommend you check out www.silencertests.com to get an idea of how many different manufacturers there are and to see some test results.