Previous EuroHacker Magazine, issue #2 Next

A few words on suppressors for the do-it-yourselfer

Written by: who knows? I dunno

This article is written with the amateur in mind, or perhaps the owner of a unregistered firearm. This means that I assume that the reader possesses only a very limited knowledge of the various suppressor types, it also means that it is assumed that this person will have to fabricate his/her own suppressor.

The most suitable weapon for suppression is the one that features a non-moving barrel, this is due to the fact that any weapon with a tilting barrel will suffer from the extra weight on the end of the barrel, resulting in possible mechanical malfunctions (lockup and the like). Different weapons will be sensitive to this to different degrees, a Beretta will cope with this extra weight better than a Glock for example, and although almost any weapon might be supressed by a competent person, the best way of avoiding problems is to use the fixed barrel type. The best standard caliber for supressing is the diminutive .22LR, the reasons for this are obvious; small caliber, small powder volume, sub-sonic velocities, and a relatively low pressure during the combustion all contribute to decrease the noise.

For the owner of a rifle, maintained accuracy is of great interest, and then the "integral" type might be suitable, this type of silencer bleeds off the gas through holes drilled directly into the barrel. This type often starts to bleed the gas after only 2-3 inches of the barrel, which in turn means that the cartridge does not achieve the speed of sound even if it would have done so from an ordinary barrel. If this type is aptly made, the accuracy won't be affected at all (at least it wouldn't in any way matter on the distances suitable for the subsonic projectile). The same is true for the ordinary "can" type of supressor, which has been fabricated in more versions than one could imagine. Provided that the projectile does not make contact with any part of the can, accuracy remains unaffected. With this type, it is recommended that one uses the standard "washer" design (at least in the beginning of your "career") although these should be slanted at different angles to get the gasses themselves to aid in the trapping/redirecting. By slanting, you will get the same effect with fewer washers, thus saving weight. What's this fuss over keeping the velocity subsonic? This must be done to avoid getting a supersonic crack, because no amount of supression can overcome this. It's as simple as that... (but I bet you already knew that).

One way to increase the effectiveness of the can-type is to add a few drops of oil to the chamber nearest to the muzzle, this will help to cool down the gasses, and thus lower the noise. Actually you could use almost any type of lubricant for this, even the type usually used in the bedroom... (but don't ask me how I know this).

When it comes to pistols, accuracy might become less interesting, and smaller dimensions become the priority (for most purposes). Integral supressors are very compact, and might just be the ticket, but for those who dont possess the required tools to make this model, a "can" can be modified to suit this need. Using an ordinary can of the acceptable size, the 2 washers located foremost should feature no hole, but instead the "hole" should be covered by some sort of barrier, which the bullet penetrates. A thin layer of rubber is the preferred material for this, as it re-seals after the projectile has passed, this little alteration will do wonders for the pistol.

So how much suppression could be expected? If you have a suppressor of either type, made with love, and the projectiles do not make contact with it, a realistic sound would be quieter, or on par with an air rifle (9mm/.45), a .22 should be like the motivated clapping of hands, although those hands might belong to Schwarzenegger (but don't worry, you will learn and become increasingly better at this, just as with anything else). Since the amount of noise is very subjective to the person judging it, another indicator might be used on self-loading weapons. Shooting a couple of rounds, followed by some fired with the mechanism closed, the amount of sound should be lesser. If so, the supressor allows the sound of the mechanism to be heard, and actually does a pretty good job itself. If you´re not satisfied with this, you will have to keep the mechanism closed during firing (it becomes a single shot in practice) or you might have to switch weapon type.

I once made a suppressor for a .32 auto, thought I made everything right, but I simply couldn't get the desired amount of supression. After looking at an empty case, I realized that the gasses had burned almost half of the case black. Ergo: no amount of suppression could correct this, since the sound (gasses) went out backwards (into the ejection port), the chamber wasn't round, it looked more like a rugby ball, making the sealing of the case impossible.

Copyright 2005, EuroHacker Magazine