To suppress or not to suppress: there is no question. (A hat tip to The Bard.) Many in the preparedness community are apprehensive about the acquisition of [“Class 3”] National Firearms Act (NFA ) items. [These include machineguns, short-barreled rifles (SBR s), short-barreled shotguns (SBSs ), and sound suppressors. There is a background check, fingerprinting, paperwork required, and a $200 tax per transfer.]
There are reams of writings about “remaining under the radar”. I do not share those misgivings. Neither do tens of thousands of other legitimate gun owners. A caveat: under no circumstances should anyone build/construct/ any NFA style weapon or device. The penalties, legal and hazard to shooters are not worth the effort. If you want the right to inventory said items and you live in a state which prohibits the same, then move. Follow the legal steps required to obtain them. Sleep better. Enjoy!
First a few facts.
There are the following weapons, devices, the predominant number in civilian hands. The information is derived from Small Arms Review magazine, May 2008. Some of the numbers are civilian police, manufacturers and private security agencies. Again, the overwhelming number is in civilian hands. A grand display of this fact is the Knob Creek shoot and the hundreds (thousands?) of auto weapons matches all over the nation.
National statistics. (from the BATFE ) 158,671 suppressors. 36,536 short barreled rifles. 97,903 short barreled shotguns. 49,052 AOW  (Any other weapons). 400,739 automatic weapons. Remarkable. Again, most of these are in private collections.
There has been only one prosecution of a licensed owned or a Class 3 for misuse since the 1934 act that established the NFA regimen. A police officer used a department registered sub-gun to kill his wife. There exists no other case law according to a close friend who defends many gun related cases. There are no statistics on destructive devices (DD s) .
My home state. 2,427 suppressors. 485 short barreled rifles. 1,038 short barreled shotguns. 691 AOWs, and 5,489 automatic weapons.
My first acquisition of NFA interest was in the late 1970s. It has continued ever since.
Another fact. Any small arm up to the .50 BMG  can be suppressed, including shotguns. Except revolvers. I refer to Small Arms Review again. In my opinion the best monthly reference on small arms within most budgets.
There are number of auto weapons in my inventory. My passion is suppression. This post will concern suppressors otherwise known as “can s”.
My first acquisition was an Ingram gun in .45 ACP . Cost? $150 [, in the late 1970s.]. They are now listing near $3,500. (Investment is a great excuse for acquisition) A MAC -10 without a can is a contradiction. I acquired a RPB can with plastic wipe s. Replaced the wipes (they add noise and add inaccuracy) with a convex muzzle wipe. There are 10,000 rounds through that combo, without a malfunction. Ken Hacakthorn, in the 1980s said that this combo is “good for a gunfight in a phone booth”. I find it good to 25 yards or less. Hmmmmm….Would you prefer a slab side [M1911 ] with 8-to-10 rounds or the MAC combo with 30 rounds?
Next came the SSG in .308. I sent off to Ciener for a can. Mine was the first suppressed [Steyr] SSG  69 in the nation. Reduces report to a dull thud when heard downrange. Adds accuracy as almost all muzzle cans do. If you acquire such, match projectile to twist. Use full power loads, ball or whatever. Most subsonic ammo uses 200 grain projectiles. In the usual 1/10 twist .30 caliber weapons this could result in a baffle strike (internal) and ruin the can or the weapon. Same goes for light projectiles. Match projo with twist. Enjoy.
Then a Ciener can for the .223 788 Remington. Death to varmints. In the ensuing years there has been added; a Ciener Ruger MKI with integral suppression. Also a Johns Guns 10/22 , again integral.
A note on integral suppression. All integrally suppressed cans are meant to be shot with high velocity ammunition. These manufacturers port (drill holes) in the barrel close to the chamber. Usually the barrels are shortened in handguns. It is critical to use the right ammunition. Do not use the Mexican Aguila .22 60 grain ammo. Remember, match twist with projectiles! Baffle strikes [very bad things] are most common in .22 rimfires. The suppression quality is astonishing in .22s. Some makers build their products to be easy to self maintain/clean. Ciener did not. Johns guns and others do. Inquire before purchase.
For quiet elimination of pests I have a Ruger 77/22 with a can from Gary’s Guns Inc. of Waukesha, Wisconsin. Cheap and effective. There is also a Marlin .17HMR with a Gemtech can. I spoke with Dr. Phil Dater about this one. He enjoyed prairie dogging so much with his .17 he had to invent a can for idid.
Other cans are Gemtech on an M16 . There are significant reports of serious hearing damage to troops in Iraq due to shooting inside buildings or vehicles. Cans prevent this. The downside, cans superheat in full auto fire and are best employed in semi-auto. Cans also blowback lots of fouling due to their gas entrapment. Malfunctions increase with the use of cans on auto weapons. Its a tradeoff most preppers could accept. I do.
The M92 Beretta, the Walther.22, the Marlin Camp Carbines in .45 ACP and 9mm, and other do nicely with cans.
Ciener made a nice can for one of the bolt guns.from Old State Arms Company (They make .50 caliber rifles)
There is also a Gemtech can which I can transfer between either of my two Bushmaster .308s.
There are a total of 17 cans in my inventory. I have also fired cans on the HK  MP5 (integral), The MK2 STEN  (integral) Both ran well. (I am a certified instructor with HK).
Needless to say further acquisitions are planned.
Preferences. Many states, mine own included, have no law or administrative code on using cans for hunting. Be sure to check your state laws and fish & game regulations!
I prefer muzzle cans with the Gemtech Bi-lock mounting systems. Threaded muzzle cans should come with a thread protector when the can is dismounted. My MK1 Ruger from Ciener had to be disassembled after 5,000 rounds or so. I had to take it to a gunsmith to dismount due to sealants which Superglued the assembly shut.The lesson here: If you require repairs/maintenance that you cannot do yourself, Make sure that your repair point is in possession of the proper Federal License. Ordinary gunsmithies cannot take in such work. you hand over a NFA weapon or device for repair, and you are not present [in the shop from beginning to end] for said work, then that is an illegal transfer. Illegal. ‘Nuff said?
There is a plethora of can makers in the market. I have cans from Ciener (no longer manufacturing cans) Gemtech is among the best. RPG is defunct. AWC makes good stuff, as does Special Ops Shop and others.
Cans are cheap. Most running $200-to-$900 depending on integral (you pay for the gun too)…Bi-locks and muzzle boosters add to costs.
Wet versus dry cans. I have hundreds of rounds through “wet” cans. Some require filling with water. Others require grease packing. Water (wet) cans require refilling to maintain efficacy. A pain in the gunfight. I have one grease pack can. Effective on the Marlin Camp Carbine. Leaves a smoke signature after rapid fire, which is not good. Without a booster, it causes malfunctions on the Glock 21.
Lesson, stick to dry cans.
Cost to register [each item in the U.S.]? $200. – Mr. X