Surely Someone Has...

[Born Hunter 17,751]

 

It's not that load, lol. I find the crack of a 22 head shot just as disturbing as the sonic crack of a 17 bullet. I recently put my SAK on my hmr having disappointingly rendered my Sirocco useless, personally I think the Sirocco was superior.

 

I've never tried a 17 cal specific mod, I think that's half the problem, all standard mods are 22 cal.

 

 

As I understand it, the speed is irrelevant. Once you break the sound barrier you break the sound barrier, it doesn't matter by how much.

 

The size of the boom (crack) is related to the size of the object causing it and thus the amount of air moved, so the larger the calibre, the larger and heavier the bullet and the larger the boom.

 

 

Without researching it I'm fairly sure that the dB level of the shock wave is caused by the instantaneous pressure change (what characterises a shock wave) which I believe will be a function of velocity as well as projectile geometry. Bullet mass/weight won't have any direct influence.

 

Simply, a faster bullet will cause a greater disturbance, thus a greater pressure change, thus a louder 'crack'........ I believe...... LOL

[Alsone 789]

I'm no expert but the Wikipedia suggests that the larger the object the bigger the boom and the faster the object is travelling the quieter the boom becomes : https://en.m.wikipedia.org/wiki/Sonic_boom

[andyf 144]

I had a Wildcat Whisper on my .17 CZ American carbine, it definitely looked the part, all steel, O rings, fully strippable etc

However (in my opinion) it was no better than the SAK I had 'in the drawer' beforehand.

However the 17HMR was still too loud, Ammo too expensive and anyway not much good for my purposes, so it went.

I replaced it with a 22.250 Ruger #1 and put a Hardy Gen2 on it, and honestly on open ground the '250 is no worse than the 17.

[Born Hunter 17,751]

I'm no expert but the Wikipedia suggests that the larger the object the bigger the boom and the faster the object is travelling the quieter the boom becomes : https://en.m.wikipedia.org/wiki/Sonic_boom

 

That's fair enough, you're right. I couldn't see how velocity would have no effect, but I was wrong about the direction of that effect. Makes sense when you think about it, the energy in the shock wave becomes less dense due to being stretched out by the increased velocity.

 

Soooooooo now we have decided that the theory says a moded 300winmag is quieter than a 308win?

[David Aiken 253]

I've always wondered how they get on with the.17 HMR in the good old US. I mean, if they generally can't moderate their rifles, there're dealing with 155 dB or there abouts!

[Deker 3,478]

I've always wondered how they get on with the.17 HMR in the good old US. I mean, if they generally can't moderate their rifles, there're dealing with 155 dB or there abouts!

 

 

 

Well, that's a lot less than most all the centrefires they use!

 

And not much different to .22lr HV and WMR which are both popular in the US.

 

Edited May 20, 2016 by Deker

[CharlieT 32]

I've always wondered how they get on with the.17 HMR in the good old US. I mean, if they generally can't moderate their rifles, there're dealing with 155 dB or there abouts!

 

Not only the states, it's only reletavley recent that you could get a moderator for anything other than a .22rf. I've never known a fox or deer complain.

[David Aiken 253]

 

 

I've always wondered how they get on with the.17 HMR in the good old US. I mean, if they generally can't moderate their rifles, there're dealing with 155 dB or there abouts!

 

 

Well, that's a lot less than most all the centrefires they use!

 

And not much different to .22lr HV and WMR which are both popular in the US.

 

Still, pretty loud for a small round. My point was, yes an unmoderated deer calibre center fire is loud, but generally a single shot?? Where as how do they (US) shoot multiple small vermin at say 50 to 100 yards with an unmoderated .17 HMR?? Doesn't the first shot send everything running for cover?

 

Noise levels of firearms:

.22 caliber rifle 130dB

.223, 55g. Commercial load 18" barrel 155.5dB

.243 in 22" barrel 155.9dB

.30-30 in 20" barrel 156.0dB.

7mm Magnum in 20" barrel 157.5dB.

.308 in 24" barrel 156.2dB.

.30-06 in 24" barrel 158.5dB. In 18" barrel 163.2dB.

.375 18" barrel with muzzle brake 170 dB.

.410 Bore 28" barrel 150dB. 26" barrel 150.25dB. 18" barrel 156.30dB.

20 Gauge 28" barrel 152.50dB. 22" barrel 154.75dB.

12 Gauge 28" barrel 151.50dB. 26" barrel 156.10dB. 18" barrel 161.50dB.

.25 ACP 155.0 dB.

.32 LONG 152.4 dB.

.32 ACP 153.5 dB.

.380 157.7 dB.

9mm 159.8 dB.

.38 S&W 153.5 dB.

.38 Spl 156.3 dB.

.357 Magnum 164.3 dB.

.41 Magnum 163.2 dB.

.44 Spl 155.9 dB.

.45 ACP 157.0 dB.

.45 COLT 154.7 dB.

[Alsone 789]

 

That's fair enough, you're right. I couldn't see how velocity would have no effect, but I was wrong about the direction of that effect. Makes sense when you think about it, the energy in the shock wave becomes less dense due to being stretched out by the increased velocity.

 

Soooooooo now we have decided that the theory says a moded 300winmag is quieter than a 308win?

 

 

As I said no expert. I'm guessing once you get out of RF territory, the issue comes more from the muzzle report than the supersonic crack as a moderator only moderates and doesn't eliminate the muzzle blast. More powder = more gases = bigger bang. Hence why some more powerful smaller CF calibres might be louder than a less "hot", larger calibre. However, as I said no expert and merely speculating here. However, larger gas volumes escaping the moderator make sense as being source of increased noise where it can't be accounted for by the supersonic side of things..

Edited May 20, 2016 by Alsone

[Deker 3,478]

 

 

I've always wondered how they get on with the.17 HMR in the good old US. I mean, if they generally can't moderate their rifles, there're dealing with 155 dB or there abouts!

 

 

Well, that's a lot less than most all the centrefires they use!

 

And not much different to .22lr HV and WMR which are both popular in the US.

 

Still, pretty loud for a small round. My point was, yes an unmoderated deer calibre center fire is loud, but generally a single shot?? Where as how do they (US) shoot multiple small vermin at say 50 to 100 yards with an unmoderated .17 HMR?? Doesn't the first shot send everything running for cover?

 

Noise levels of firearms:

.22 caliber rifle 130dB

.223, 55g. Commercial load 18" barrel 155.5dB

.243 in 22" barrel 155.9dB

.30-30 in 20" barrel 156.0dB.

7mm Magnum in 20" barrel 157.5dB.

.308 in 24" barrel 156.2dB.

.30-06 in 24" barrel 158.5dB. In 18" barrel 163.2dB.

.375 18" barrel with muzzle brake 170 dB.

.410 Bore 28" barrel 150dB. 26" barrel 150.25dB. 18" barrel 156.30dB.

20 Gauge 28" barrel 152.50dB. 22" barrel 154.75dB.

12 Gauge 28" barrel 151.50dB. 26" barrel 156.10dB. 18" barrel 161.50dB.

.25 ACP 155.0 dB.

.32 LONG 152.4 dB.

.32 ACP 153.5 dB.

.380 157.7 dB.

9mm 159.8 dB.

.38 S&W 153.5 dB.

.38 Spl 156.3 dB.

.357 Magnum 164.3 dB.

.41 Magnum 163.2 dB.

.44 Spl 155.9 dB.

.45 ACP 157.0 dB.

.45 COLT 154.7 dB.

 

 

I see where you are coming from, but figures can say whatever you want.

 

The internet can be a dangerous place, I found this in a couple of minutes....

 

.22 lr: Subsonic Ammunition (Eley Hollow Extra Plus)

Noise reading taken from the side of the gun with SAK silencer was 97db and without silencer was 107 db (A-weighted)

 

.22 lr: High velocity Ammunition (CCI Stinger)

Noise reading taken from side of the gun with SAK silencer was 113db and without silencer 113 db

Noise reading at the muzzle with silencer was 105db and without 109db

 

.17HMR: (Hornady V-max)

Noise reading taken form the side of the gun with SAK silencer was 111db and without silencer 113 db

Noise reading at the muzzle with silencer was 114 db and without silencer was 116 db

 

At the shooters ear the results suggest that the HMR is slighly quieter that .22HV but is quite a bit louder at the muzzle. I'm interested what happens down range and typically the HMR will be aimed at targets further away than .22 lr. Standard .22 subs using a silencer are quieter than many air rifles, I've got spring guns that will go well over 100 db at the side of the gun

 

That is seriously different to your HMR figures.

 

I know what my ears hear, but who knows what its like at point of bullet arrival?

 

 

[Alsone 789]

I agree with Deker on air rifle point. I had a moderated precharged and my friends moderated .22 finfire was considerably quieter with subs. It's also interesting to note that in some hmr videos of rabbit shooting at longer ranges, the rabbits around the target animals aren't spooked by the shot.

[Graham M 36]

(Pops head over parapet)

I have a SAK on mine and it's quite good. and if it wears out in a couple of years then it isn't too expensive to replace.

 

[foxtrotoscar 35]

Come up with a silencer that "really!!" Works on a .17 HMR?

 

Who's not talking and keeping something secret

There has to be someone fettling away in a workshop somewhere.

Please spill

I've tried saks, siroccos , ruag and several others but the best by far is the Hausken 17 calibre specific mod which gets quieter as it gets dirtier it appears. Cracking moderator for the HMR.