Dragon Slayer 50 cal.

Hello. I have a Dragon Slayer in 50 cal. PCP and contacted Blodnob to see if he could make something to moderate its report. I know this gun cannot be completely silenced, but wanted to reduce the noise by a “reasonable” margin. Otherwise this thing is absolutely un-shootable here in my home, and I want, at least, to check zero on my scopes and test some ammo.

Blodnob agreed to build a silencer. We discussed about the method of attachment to the barrel and, considering that no barrel thread was possible, I asked him to use grub screws.

I wrote some reports to him as a way to say “Thank You”. He asked me to post them here, so here they are. Pictures are at the bottom of the post.

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A.- SOME NOISE LEVEL REFERENCES
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1.- How noise was measured
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I used a sound level meter model “Uni-Trend UT-351”, made in China/Hong Kong. It has a range from 30 to 130 Db. It is the only device of this kind available where I live and I have no idea if it is good or bad quality. At least it has all the necessary functions to let me read noise from an airgun the way I want. I read here and there that absolute measures from such a device are useless, not only because they all have different calibrations, but also because the conditions of the environment affect measures considerably, and they are difficult to reproduce, etc. For instance, if you tell me that your 22 rimfire is 120 Db. and I tell you that my 22 rimfire is 114 Db., then that would mean absolutely nothing!!! The only thing useful is the relative measure from one gun to another, or comparing with/without silencer, etc. – but always taken with the same device and exactly in the same conditions. Even so, the measures of Db. by themselves may not give a trustful indication about the “significance” of noise, hence the subjective opinions are a useful complement.

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2.- Testing some spring-piston guns
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Prior to testing Blonob’s silencer on the DS50, I tested 4 common spring-piston airguns. This will serve as a starting point of reference:

– Gecado Mod.27 (Diana), 177 cal., 7 fpe energy.

– Beeman HW77, 22 cal. (long barrel),14.5 fpe energy.

– Beeman R1, 177 cal. (long barrel),16 fpe energy.

– Beeman Kodiak, 25 cal., 28 fpe energy.

I rank these guns exactly in this order, from most silent to loudest.

The low powered Diana is a silent gun. I can shot it all the day long in my backyard. The HW77 is another pretty silent gun. The R1 is somewhat a little bit louder than the HW77, but the noise is of a different class: the HW77 has more of a “twang”, while the R1 has a “crack” that seems to be higher in pitch. Anyways, both of them I can shoot in my backyard confidently for a long while. Finally, the Kodiak is a loud gun. It has a noticeably bark on it and one would say “it is many times louder” than the other 3. I can fire only up to 10-15 shots in my backyard…

The test was done inside my garage. I chose a place some 6 meters away from the gun to place the device. The device was placed against the gun, pointing to the gun. Yes, conditions are tricky to interpret and there is obviously some echo in this setup, but again, the goal is only to have some references.

I have a “shooting tube” which is a kind of “big frame silencer” that I use. It is made from wood and cardboard, it is 2.20 meters long (section is 50 cm x 50 cm app.), and has a special “acoustic foam” inside it, it also has several internal baffles. As I hear it, it helps a lot reducing noise when you fire through this shooting tube. It even reduces a significant part of the mechanical noise of spring-guns.

My pellet trap has “duct seal” on it, that is, it is a silent trap. I’m confident that the pellet hitting to the trap does not significantly interfere with the measures.

These are some references of basic noises with a very quite ambient inside my house: when no cars are in the street, the reading is 32-33 Db. This is like “absolute silence”, if I only breath near the device, it immediately goes to more than 40 db. With cars on the street it is 48-50 Db. A big dog barks some houses away: 55 Db, etc.

Here are the results of the springers:

Gun —- Configuration ————- Db
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Diana — without shooting tube —– 81
Diana — with shooting tube ——– 76
HW77 — without shooting tube —– 84
HW77 — with shooting tube ——— 80
R1 —— without shooting tube —- 85
R1 —— with shooting tube ——– 80
Kodiak – without shooting tube —- 88
Kodiak – with shooting tube ——– 83

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B.- “REVIEW” OF BLODNOB’S SILENCER
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1.- Finish
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The machining is top quality. The finish (matte) is even and looks professional. The 4 grub screws have a very elegant look. In general, the whole device has elegant lines on it and reveals that considerable care was taken in the design (the esthetical aspect).

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2.- Fit to the gun
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The fit to the gun is perfect. It enters tightly to the bore, no “play” is allowed, you must fit the silencer very straight. Once the edge of the silencer reaches the airtube, because of its design, it doesn’t allow -almost- any further rotation on the barrel. The grub screws hold the silencer firmly in place. I have shot some 50 rounds through it already and there are no signs of any problem, however, only time will tell if this setup remains as solid as it seems now.

It must be said that the solution of the grub screws has a weak point: it doesn’t allow to be put in and out endless times, because it is obvious that the material wont stand up for that stress endlessly. So, basically at one point you must install the silencer and leave it alone in place. This is an inherent fact to the use of grub screws. Also, another fact inherent to the use of grub screws is that they leave a mark on the bluing of the barrel, some people may dislike that.

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3.- Weight and Volume
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The aspect of the silencer (volume) looks very proportionate to the rest of the gun, remember that the bore of this gun is very fat. This gun is a “carbine” to start with, so the overall length with silencer is increased to an acceptable level. The weight of the silencer was lighter than I supposed for its volume, and I don’t feel it changes the overall balance of the gun.

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4.- Performance
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I measured noise in the same conditions as prior with springers. The results are the following:

Naked Gun: 101 Db.
Gun with Silencer: 92 Db.
Gun with Silencer and Shooting Tube: 85 Db.

There was no “clipping” felt when shooting with the silencer. I suppose that clipping, if present, would have been evident, perhaps destroying the silencer in pieces, but that didn’t happen. However, this fact (the lack of clipping) shall be confirmed once accuracy of gun is tested.

Some subjective observations about noise:

* Naked Gun:
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As said, to shoot the naked gun is almost prohibitive for me. Damn. I cannot shoot this thing more than 3 times in a single session. The measure given is actually the average of these 3 shots. After every shot my ears keep a “beep” similar as having been several hours in a discotheque. I keep this “beep” in my ears for several minutes.

* Gun with Silencer:
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Noise is tolerable. In terms of level I would rank it similar to the Kodiak springer, just slightly more. However, it is not the same kind of noise: the Kodiak has a higher pitched “crack” and the DS50 has a lower pitched noise with a noticeable “ping” on it. Yes! Actually now I start to hear this “ping” which is typical of PCP’s, and was not audible before. It is evident this gun will benefit a lot with the installation of a “depinger” (BTW: may someone give me indications on how to disassemble this gun??? please PM me!!!). Another difference between the Kodiak and the DS50 is that the DS50 displaces a lot of air, so, besides the noise, it also seems to have a “wave” of air that “moves” things around you. It is difficult to explain, but when you shoot it, you certainly feel it. Now, I wouldn’t shoot this in my backyard for a long period of time, but no problem for 10 shots or so.

* Gun with Silencer and Shooting Tube:
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Now this is good!! Noise is in the same level of the HW77 or the R1 springers, and that can be shot for quite a while (shooting from the inside of my garage to the backyard). This is the setup I needed.

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5.- Conclusions
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I am very pleased with Blodnob’s work. The design, labor and quality put in the silencer are evident. It did fulfill my expectations in performance: as said before, I knew that this gun cannot be silenced completely, and that I was looking to reduce noise by a “reasonable” margin. What is to be considered “reasonable” is personal and highly subjective, but in my case this is fulfilled because now I can shoot confidently from my garage (using my shooting tube) and zero my scopes and test some ammo.

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C.- COMPARISON WITH ANOTHER SILENCER
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I have another PCP, it is a BSA Tech Star which does 38-40 fpe power. It has a “depinger” inside the airtube, I don’t know if that affects the noise level (Db.), but certainly it changes the type of the noise. For this gun I have the Weihrauch silencer on it. I had never shot this gun unsilenced before but others have reported it to be very loud – “similar to a 22 rimfire” they said. On the other hand, the gun with silencer is, in my opinion, decently quiet. So, before conducting this test, I thought that the Weihrauch silencer was reducing the noise by a BIG margin. In fact, I thought it was a LOT more than the 9 Db. reduction of Blodnob’s silencer on the DS50, but of course this would not make a fair comparison, since the difference in calibers (Tech Star is 22), volumes, air consumption per shot, etc., are abysmal. Here are the results for the Tech Star:

Naked Gun: 94 Db.
Gun with Silencer: 84 Db.
Gun with Silencer and Shooting Tube: 77 Db.

Same as before, some subjective observations:

* Naked Gun:
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It is very loud. Even being 7 Db. lower than the naked DS50 (which is a lot) it sounds similar and produces the same “beep” in my ears, difference may be that the “beep” lasts less. Other differences: the Tech Star has a very high pitched “crack” and displaces a lot less air, so it doesn’t seem to “move” things around you, like the DS50 does. Even so, I wouldn’t risk to shoot this un-silenced thing in my backyard.

* Gun with Silencer:
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As said, this is a “decently quiet” setup. Even having similar noise measures as the HW77 or the R1, it feels to be quite less by the shooter. After thinking a while about this, I guess it is because of the mechanical noise present in the spring-piston guns. Anyways, I usually shoot this silenced gun for a long while in my backyard, with no problem.

* Gun with Silencer and Shooting Tube:
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This is what -I think- must be called “mouse fart quiet”. Noise is minimal. Now I suspect that the noise of the pellet hitting my so-called “silent pellet trap” is producing some interference in the measures.

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Conclusions
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The Weihrauch silencer reduced noise by 10 Db. which is very similar to the 9 Db. reduction of Blodnob’s silencer in the DS50. I was impressed by this fact. In my absolute ignorance in the suject, I would interpret this as Blodnob’s silencer being VERY efficient. Remember that the Weihrauch silencer is considered to be one of the most efficient airgun silencers among those commercially available, but the impressive thing is that comparison of the Tech Star to the DS50 is like talking about “David and Golliath”.

Cheers.

Bunki.

IMPORTANT DISCLAIMER: I LIVE IN SOUTH AMERICA, THERE ARE NO LEGAL ISSUES HERE WITH AIRGUNS, DISREGARD OF THEIR POWER LEVEL, OR WITH ANY AIRGUN ACCESSORIES, INCLUDING AIRGUN SILENCERS.

Now the pictures:

Details of the silencer:

The gun with the silencer mounted on it:

Details of the silencer’s attachment to gun:

The marks that the grub screws left on the barrel:

The device used for measuring noise level:

Blodnob’s silencer and Weihrauch silencer, side by side:

Tech Star w/silencer and DS50 w/silencer, side by side: