Sound suppressors for handguns offer unique benefits as well as comparably unique challenges. The cans, as they are known, do not add a great deal of bulk or weight, but do substantially enhance control of the firearm as well as reducing sound.
A state-of-the-art pistol like the Springfield Armory XD-M Elite Tactical OSP (Optical Sight Pistol) is born to accept a sound suppressor along with some rarefied accessories. Adding a can, a proper tactical light, and a micro red dot sight to the gun turns an already exceptional pistol into a close quarters room-clearing racecar. The modern handgun sound suppressor sports about as much technology as the space shuttle.
Pistol Physics
The speed of sound in dry air is about 1,125 feet per second. Anything traveling faster than that magic number is going to make a troublesome sonic crack. That means standard 9mm is supersonic, while .45 ACP is not. However, it’s not quite that simple.
The big honking hole in the end of a pistol can is going to let a fair amount of racket escape no matter how fancy or high-tech a sound suppressor’s entrails might be. Subsonic ammo is available in most all common pistol calibers, but the exit pupil will typically be larger in pistol cans than in their rifle counterparts. Fortunately, subsonic 9mm rounds are both readily available and relatively inexpensive these days.
Mechanical Practicalities
Autoloading handguns are relatively delicate little machines. The construction and materials science may be tougher than an M1 tank, but the physics of turning recoil energy into a reciprocating action is always going to be a little tight. Pistol rounds just don’t have a great deal of excess spunk to drive an action. An answer to this sticky quandary is the Linear Inertial Decoupler, or Nielsen Device.
The vast majority of the duty- and defensive-style pistols in the world today run off of John Moses Browning’s inspired tilting-lock recoil-operated action. When you hang the extra mass of a sound suppressor onto the barrel, however, the action will typically fail to cycle. The L.I.D. captures a little bit of the excess chaos at the muzzle and uses it to give the front of the gun a helpful little tap. The Nielson Device is the most inspired human contrivance since the flush toilet.
Different pistons inside the device will allow the same can to swap between different platforms. A dirty little secret in the suppressor industry is that a .45 ACP can works almost as well on a 9mm platform as might a dedicated 9mm suppressor. This means a .45 ACP suppressor with a couple of spare mounts can service a wide variety of host firearms with a single transfer tax.
Entrails
The internal design of a pistol can is fundamentally similar to that of a rifle or rimfire suppressor. While there are literally dozens of ways to skin this cat, the most common is by use of stackable K-baffles. These nifty little doodads are so designated because if you were to section them down the center they would form a K.
These baffles slow the escaping muzzle gases and cool everything down to excise the snap from a pistol shot. To really enhance the efficiency of a pistol suppressor you can squirt a little ablative material down into the thing before hitting the range. Adding something that can be vaporized substantially increases the capacity of the suppressor to dissipate heat and kinetic energy, subsequently diminishing the noise.
Wire-pulling gel works well but is messy. So is Vaseline. WD40 is good for a few shots but doesn’t last. Urine works in a pinch, but so long as I’m not humping the Hindu Kush in search of trouble I’m not peeing into my sound suppressor.
Options
The Gemtech GM9 and GM45 are monocore designs wherein the entire baffle stack is cut from a single cylinder of aluminum. This facilitates disassembly and cleaning for a mild reduction in efficiency. These cans are lightweight and sufficiently thin to allow you to use suppressor-height sights like those on the Springfield Armory XD-M Elite Tactical OSP.
The Gemtech Lunar 9 is a modular design that allows the suppressor to be configured as a high-efficiency 7-inch unit or an ultra-compact 4.7-inch can. The baffles are removable for cleaning, and the can uses standard GM9 mounts. The Lunar 9 is full-auto rated and truly hardcore.
The SilencerCo Omega 45K is a sealed suppressor that cannot be disassembled at the user level. However, I have run a zillion rounds through mine with no degradation in performance. I’m not really sure that sound suppressors much need cleaning. The Omega 45K is remarkably effective, utterly rugged, and runs great on both 9mm and .45 ACP platforms with the proper mounting systems.
Denouement
You don’t buy a pistol can so you can quietly infiltrate some evil despot’s secret lair. You get a pistol can so as not to unduly offend the neighbors and still retain the capacity to communicate should you ever have to run your pistol indoors. I still wear earplugs with mine when I’m just out having fun. However, in addition to all that good neighbor stuff, a decent pistol can hanging on the snout of your XD-M Elite Tactical OSP does indeed look undeniably awesome.