Many factors must be considered when selecting a suppressor (silencer). The primary question is what type of weapon will be suppressed. The intended use of the suppressor then must be evaluated.
Pistol vs. Rifle Can
Many people equate suppressors (cans) with pistols as the most common platform. This use is often inappropriate. Suppressed pistols have their place with short range duty but they cannot compare with the accuracy and comfort of a suppressed rifle at longer distances. Scopes may be necessary for longer distance shooting. They are often not suitable for mounting on pistols. A suppressed rifle with a scope is the preferred tool for varmint control. The bigger the varmint, the larger the caliber rifle and the larger the scope.
The author has drafted many NFA gun trusts for Texas residents whose farms and ranches are plagued with pesky hogs. These farmers and ranchers use the trusts to purchase suppressors for their rifles used to eliminate this ongoing problem.
Integral vs. Can Suppressor
There are basically two types of suppressors: integral and screw on (including quick release). An integral suppressor is one which is built into the weapon. An example is the Hi Standard HD Military .22 cal. suppressed pistol. This was a favorite of the OSS used for assassinations in World War II. This gun has been reproduced by several manufacturers in recent times. It is still a favorite due to its function, looks and reliability. This weapon has a suppressor which screws on to the threaded barrel which is ported (holes drilled therein) to dispel the gas and sound into the suppressor baffles and tube as a round is fired. This process dampens the sound of the round being fired but also slows the speed of the projectile. The MP5SD suffers from the same problem.
Ported Barrels – Pressure Loss
Several years ago the author purchased an HK 94 9mm rifle. He carefully selected a skilled gunsmith to shorten and port the barrel and remark the gun. After a lengthy but well deserved wait Mr. Ralph Smith of RTDS (Reg Dog Target Supply) of Cave Creek, Arizona, created a masterpiece. He turned the old HK in to a beautiful MP5 SD Navy. The old gun was now properly remarked and registered as an SBR (short barreled rifle) with a custom suppressor carefully fitted to a ported barrel. Ralph transferred the sear from an old steel registered HK trigger pack and mounted it in a new HK ambi-4 position Navy polymer lower. The end product looked so good it sat in the author’s safe for years for fear of scratching this true work of art.
Nevertheless, the MP5 SD has its drawbacks. The most serious problem is lack of knockdown power. So much gas is bled off by the ported suppressed barrel that the fired rounds have much less energy than rounds fired from an unsuppressed MP5 weapon. An MP5 with a screw on or three lug can has much more “fire power” than its suppressed MP5 SD mate with ported barrel. This is because not as much gas is lost with the “normal” MP5. Of course, the MP5 SD is usually much quieter, but if the intended use requires more “knock down power” the MP5 should be used instead. Many law enforcement agencies maintain both of such weapons for such reasons.
Knock down power is usually not an issue with small caliber cans where the use of subsonic ammunition is common. Subsonic ammunition is for the most part much quieter than regular .22 ammunition but is also more expensive. Sometimes less expensive standard velocity .22 ammunition is nearly as quiet a the subsonic ammo. Yet the selection of the correct platform is still important.
Suppressed pistols are accurate at short distances where suppressed rifles are far better at longer ones.
Screw on cans are usually relatively inexpensive and can be used on rifles or pistols with threaded barrels. The thread pitch for .22 cal. suppressors is usually ½ x .28 which is also the standard thread pitch for an AR15 or M16 rifle. Suppressors are usually ammunition sensitive with some functioning better with certain types of ammunition. A suppressor might work better on a certain rifle or pistol with markedly different degrees of sound reduction. All suppressors are for this reason not created equally. Some suppressors are prone to an annoying “first round pop” – a loud seemingly unsuppressed retort which is followed by much quieter subsequent rounds. The sound signature of many suppressors is different. Suppressors rated with the same db (decibel reduction) rating may not sound alike. One may have a much deeper richer tone while another may have a higher pitch.
Next the same suppressor’s sound reduction characteristics may vary from rifle to rifle and pistol to pistol displaying slightly different harmonics. This may be due to barrel length, back-pressure or other factors.
Suppressed Bolt Action Rifles vs. Semi-Auto Rifles
Generally a suppressed bolt action rifle will be much quieter than a semi-auto model even when both have integrally suppressed barrels. This is so because the gas (and sound) escapes through both the barrel and the action when the semi auto bolt cycles and the next round is loaded into battery. Put another way, with the bolt action rifle, the sound and gases are expelled from the barrel end only while the semi auto expels sound and gas from both ends. (No pun intended). In practical terms a Ruger 77/22 (bolt action) with a suppressed barrel will usually be much quieter than an suppressed Ruger semi- or full auto 10/22 rifle.
There are numerous manufacturers of suppressors which make various claims of sound reduction. They also make the traditional screw-on, three-lug mount, and quick connect/disconnect mounting features.
Look and Listen Before Your Purchase
Before purchasing a suppressor it is best to research the sound reduction attributes when mounted on different guns. There are several web sites which offer this information. Some of the best selections are made in the field listening to someone else firing a suppressor that you might consider purchasing. The author did just this at a machine gun shoot outside of Center Point, Texas. At the Memorial Day shoot many in attendance had suppressors mounted on their AR-15 and M-16 rifles. Some bore quick-connect suppressors which seemed to have excellent sound reduction qualities. Nevertheless, at the end of the day when several of these suppressor owners attempted to remove their “quick disconnect” suppressors they were met with an unpleasant surprise. Many of the “quick disconnect” suppressors would not disconnect at all. The gunk which had built up during the sustained fire had melted into the barrel threads making the suppressors quite difficult to remove. After seeing this the author continued to purchase the screw on type suppressor leaving others to battle those with the “quick disconnect” problems.
About the Author
The author, Martin Seidler, is a former member of the Junior 29er’s rifle club in Miami, Florida where he shot small bore competition in the 1970’s. After graduating from Miami Beach High School, he attended the University of Florida at Gainesville where he graduated with honors. He then attended St. Mary’s Law School in San Antonio, Texas and entered the private practice of law. He later became a panel bankruptcy trustee under the U. S. Department of Justice U.S. Trustee program where he administered thousands of bankruptcy cases in south Texas and litigated numerous contested matters over the years. He now practices law in San Antonio, Texas, handling bankruptcy, personal injury, home equity loan avoidance cases and estate matters drafting wills and NFA trusts for those who wish to acquire Class III weapons and suppressors. He also assists veterans and the elderly with their financial and legal problems. He still enjoys building and shooting machine guns when time permits.