How Do Suppressors Affect Accuracy — Surprising Test Results

Are sound suppressors useful in competition shooting? In some disciplines, and in venues where sound “moderators” are permitted, the answer is “yes”. In the November edition of Shooting Sports USA eZine, you’ll find an interesting article about the use of sound suppressors (aka “cans”). The article explores the use of suppressors in Europe and in tactical matches in North America. You’ll also find an explanation of the rules and regulations governing suppressor ownership and use in the United States.

Shooting Sports Editor Chip Lohman tests three rifles from the bench and found that sound suppressors did not harm accuracy. In fact, all three test rifles (one each in .223 Rem, .308 Win, and .338 Lapua Magnum), shot slightly better 5-shot groups at 200 yards when a suppressor was fitted to the barrel. However, the suppressors did alter point of impact. Interestingly, velocity standard deviation (SD) values were lower with suppressors in place for all three test rifles. This observation calls for further study.*

So the use of suppressors in competition could be a good thing. However, in the United States, current NRA rules prohibit the use of sound suppressors. NRA Rule 3.16.1 subsection (a) states: “Sound Suppressors are not authorized for use in High Power competition.” In addition, there are some practical problems with suppressors — the heat rising off of a naked suppressor can create mirage problems (that’s why some shooters wrap their cans with a cover).

Despite such issues, now commonly see suppressors on rifles used in tactical matches and PRS/NRL events. For example, many competitors in the Steel Safari field challenge match use suppressors. The photo below shows our friend Zak Smith competing in the Steel Safari with his suppressed Accuracy International rifle.

Commentary — What Can We Conclude?
Obviously, this three-rifle SSUSA test was not definitive. One well might observe different results with different types of suppressors, fitted to different kinds of rifles. Mounting a suppressor to any barrel will certainly affect harmonics and “tune”. But this SSUSA study does suggest that tactical shooters, who are allowed to use suppressors in competition, may find that the benefits of suppressors (significantly reduced recoil and less noise) outweigh any meaningful accuracy loss, at least in PRS-type matches.

NOTE: The article cautions that one should not extrapolate too much from the SD numbers, given the low number of test shots. Chronograph-maker Ken Oehler, when asked to comment on the SD values stated: “[You should] report the observed SDs, but draw no conclusions until… you can do more testing with larger sample sizes.”

Qualifications to Obtain a Suppressor

To legally obtain a suppressor, you must fill out Federal Forms and pay a $200 fee to the ATF. You must also pass BATFE background checks and otherwise comply with Federal and state laws. States can regulate suppressor ownership or use, so be sure to check the laws in your area. On the federal level, the process to acquire a suppressor is regulated under the National Firearms Act of 1934.

PURCHASING TIP: ATF Announces New e-Form 4 Platform for Suppressor Registration

Similar Posts:

• Do Suppressors Degrade Accuracy? Silencer Myth-Busting
• Sound Suppressors Tested in Shooting Sports USA Article
• Suppressor Myth Busting — Do Silencers Degrade Accuracy?
• Can-Can: Hunting with Suppressors Now Legal in Montana
• Sound Suppressors for Target and Varmint Rifles

Tags: Can, Chip Lohman, Noise Reduction, PRS, Shooting Sports, Silencer, Sound Moderator, Sound Suppressor, SSUSA, Suppressed, Suppressor Accuracy, Tuner Brake, Zak Smith