PCP Silencers from Nielsen

 PCP Silencers from Nielsen

Background

If you have only ever shot a rifle or pistol, you may be surprised to learn that the Pre-Charged Pneumatic (PCP) rifle discharge of only dry air, can be quite loud. Not loud enough to warrant wearing ear protection (IMHO). However, the sound levels will be somewhat dependent upon the following parameters but not limited to: the volume of expanding  air and the duration of that expanding air after the projectile has left the muzzle. of course this latter parameter should be minimised for optimal operation of the weapon and hence to reduce the unnecessary use of air from the tank. Generally for high quality PCP rifles, many parameters are able to be easily adjusted by the user.  Un-moderated sound levels can easily frighten game and of course disclose the position of the shooter , just as they can for a firearm.

One gun parameter that can not be adjusted by the user and that is the emission of sound, unless a moderator or more commonly known as a silencer, is used. The silencer for a PCP weapon works using a similar principle to that of a silencer for a real firearm. There will be a high volume expansion chamber directly adjacent to the muzzle, which will generally not cover the barrel unlike certain silencers designed for firearms. Following the expansion chamber there will be some sorts of baffles of proprietary designs to reduce the expanding gas velocity and hence limit the sound emission exiting the silencer. As for these baffle designs, well it appears there are a plethora of designs out there however, the only way to really judge whether they work or not is simply by measuring the sound emission in a standard way and conducting repeatable tests, regardless of whether these things are filled with "cosmonium alloys" from mines on IO or jelly beans!

In this blog and following video I will be exploring the reduction of sound level by using a high quality silencer manufactured in Denmark specifically for PCP weapons by Nielsen Gun Parts. I will be reviewing the following model silencer: SUB SONIC-35 0.22cal (Nielsen's range covers 0.177 cal to 0.22 cal) which forms part of the high quality SONIC line (21 different silencers across 6 different groups") of rifle accessories from Nielsen.

Nielsen Gun Parts is a Danish company and is part of J. Nielsen Design, who are staffed by experienced engineers with many years experience with hunting rifle and accessories manufacturing. Jørgen Nielsen is the man behind the designs, a hunter with over 40 years experience in weapons manufacturing. To find out more about Nielsen Gun parts see here

This is the SUB SONIC-35 0.22cal  (22-12158) silencer from Nielsen in Denmark (Danmark). 

It comprises of five "modules", the initial 1/2" x 20 UNF threaded female expansion chamber (or blast chamber in the case of a real firearm), followed by 5 conical baffles (modules). 

The construction of this model is entirely made from  aluminium and anodized black. 

Showing the 1/4" x 20 UNF female thread. (note a PCP adaptor of a male 1/4" x 20 UNF is required for mounting) to a PCP rifle.

Internal view of the first baffle/module facing the expansion/blast chamber.

The reverse side of the same module. Note all the modules on this silencer are the same. The shape here again allows for immediate expansion of gases.

For legal requirements, the silencers are not shipped assembled outside of Denmark (for obvious reasons), so what you see here is a fully assembled 0.22 cal SUB SONIC silencer.

All of the modules came with a generous (but not excessive) amount of grease on all threads to prevent binding. Since the test will be carried out on a PCP, unlike a regular firearm the use of high temperature resistant grease is not necessary in this case.

The above image shows the inside of the first chamber. 

The rifle for testing has an approximate barrel volume of 14ml.

The volume of discharged air depends on the rifle settings.

Nielsen SONIC silences come in a variety of thread sizes.

As the LASER engraving shows, Made in Denmark (and before anyone say's hey they got the spelling wrong-no they didn't! This is how Denmark is spelt in Danish.

You can see Nielsen's products here

 Stay tuned for the field testing Results on Bush camping Gear!