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Posted: 3/29/2009 10:57:06 AM EST
[Last Edit: 6/13/2009 6:12:47 PM EST by popnfresh]
Has anyone made a bullet trap that is hearing friendly as in not detectable to the neighbors? I want to make a box that I can test loads for function before taking them to the range. My range charges $10 per gun, I hate to waste the time and money on a trip to the range only to find that a load is non functional. I want to make a box that I can test a load for function with out the neighbors calling the cops about shots fired .


UPDATE
OK about 150 hours of labor, $540 worth of building materials, and a 1000+ lb monstrosity later........ It works as I had hoped but I highly doubt it was worth it ....... I am stubborn and had to finish it regardless.
Here is the long boring video of it in action with my decibel meter >>>VIDEO<<< . The meter is to get a ROUGH idea of the difference between the different rounds and to compare to a hammer strike on wood, a normal sound that wouldn't be questioned by an outside observer like a neighbor. I realize I was using the "c" weighting setting and the below data is taken in "a" weighting.


Here is some info from this page http://74.125.47.132/search?q=cache:h4eAQjiSPA8J:www.keepandbeararms.com/downloads/SoundAdvice.doc+sound+pressure+levels+of+various+handguns&cd=9&hl=en&ct=clnk&gl=us&client=firefox-a

Table 2. SHOTGUN NOISE DATA (DECIBEL AVERAGES)
.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

CENTERFIRE RIFLE DATA
.223, 55GR. 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" barre.....l 156.2dB
.30-06 in 24" barrel .....158.5dB
.30-06 in 18 " barrel .....163.2dB
.375 18" barrel with muzzle brake..... 170 dB

CENTERFIRE PISTOL DATA
.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


Here are the pics of the cunstruction.























Link Posted: 3/29/2009 11:15:40 AM EST
Originally Posted By popnfresh:
My range charges $10 per gun,


Time to find a new range! Jeez.....as if ammo wasn't bad enough....



Link Posted: 3/29/2009 11:40:27 AM EST
Originally Posted By popnfresh:
Has anyone made a bullet trap that is hearing friendly as in not detectable to the neighbors? I want to make a box that I can test loads for function before taking them to the range. My range charges $10 per gun, I hate to waste the time and money on a trip to the range only to find that a load is non functional. I want to make a box that I can test a load for function with out the neighbors calling the cops about shots fired .


Have you fallen down in your bath tub and hit your head causing yourself to slurp up too much bathwater ???? Because that question might lead one to think so. But hey, I'll help you in your madness. Buy blocks of ballistic gel or you can shoot into a 55 gallon barrel of water. As for the noise ??? Equip your neighbors with ear plugs or sound proof a room in your basement. Surely you don't have kids in the house....... Spend the ten bucks and go to the range.
Link Posted: 3/29/2009 12:05:14 PM EST
short of using a legal silencer, I can't imagine getting anything centerfire quiet enough to be used without neighbors beoming concerned. Now if you were talking about 22LR, they do make bullet traps for those. I know a guy who has one and with an old phonebook stuffed in it, it is very quiet. When shooting thru a 10/22 using CB ammo, it is almost undetectable to neighbors. Course I will say shooting any firearm in most city limits would be illegal so I could not recommend trying it. Oh and the obvious warnings would apply too since a stray 22 bullet could be dangerous.
Link Posted: 3/29/2009 12:26:21 PM EST
Savage Snail Trap. Quiet? Yes. Expensive? Do you have to ask?

Yep, same people who make great rifles.
Link Posted: 3/29/2009 12:43:09 PM EST
there are probably laws in your area about firing guns so close to houses.
Link Posted: 3/29/2009 12:50:26 PM EST
Originally Posted By gmtech825:
there are probably laws in your area about firing guns so close to houses.


Savage Snail traps are not only deathly silent, they are vented to the outside, keeping lead out of say, the basement. They sound like someone driving a nail. There is a rubber seal the barrel is put though to seal the firing chamber.

Since it doesn't attach to the firearm and is not portable, it isn't a silencer. Furthermore, it prevents the exit of the bullet.

Check it out..

Link Posted: 3/29/2009 1:11:15 PM EST
Originally Posted By 1911smith:
Originally Posted By popnfresh:
Has anyone made a bullet trap that is hearing friendly as in not detectable to the neighbors? I want to make a box that I can test loads for function before taking them to the range. My range charges $10 per gun, I hate to waste the time and money on a trip to the range only to find that a load is non functional. I want to make a box that I can test a load for function with out the neighbors calling the cops about shots fired .


Have you fallen down in your bath tub and hit your head causing yourself to slurp up too much bathwater ???? Because that question might lead one to think so. But hey, I'll help you in your madness. Buy blocks of ballistic gel or you can shoot into a 55 gallon barrel of water. As for the noise ??? Equip your neighbors with ear plugs or sound proof a room in your basement. Surely you don't have kids in the house....... Spend the ten bucks and go to the range.


I don't see anything wrong with the question.

Why does it bother you?
Link Posted: 3/29/2009 1:24:33 PM EST
Originally Posted By Keith_J:
Originally Posted By gmtech825:
there are probably laws in your area about firing guns so close to houses.


Savage Snail traps are not only deathly silent, they are vented to the outside, keeping lead out of say, the basement. They sound like someone driving a nail. There is a rubber seal the barrel is put though to seal the firing chamber.

Since it doesn't attach to the firearm and is not portable, it isn't a silencer. Furthermore, it prevents the exit of the bullet.

Check it out..



I wouldn't say their deathly silent.
It's still a remarkable event when someone touches one off in it, especially if they forgot to shut the door to the room.
Link Posted: 3/29/2009 2:21:07 PM EST
I had a gunsmith in a nearby town test fired my rifle outside his shop, in a neighborhood. It was some sort of trap, looked like steel sides, filled with sand, and had what looked like a lid from a 5 gallon bucket on top. The "lid" had a hole in it with what looked like strips of rubber/carpet and he stuck the muzzle in and touched off a round of .308. Very quiet. It sat at about a 45* angle, on some sort of rack to support it. I don't know if he built it, bought it or what. Worked well.
Link Posted: 3/29/2009 2:45:36 PM EST
Originally Posted By buzzworm:
I had a gunsmith in a nearby town test fired my rifle outside his shop, in a neighborhood. It was some sort of trap, looked like steel sides, filled with sand, and had what looked like a lid from a 5 gallon bucket on top. The "lid" had a hole in it with what looked like strips of rubber/carpet and he stuck the muzzle in and touched off a round of .308. Very quiet. It sat at about a 45* angle, on some sort of rack to support it. I don't know if he built it, bought it or what. Worked well.


I have this in my workshop. I have since changed the lights over the chrono to incandescent. It's still loud even with the door to the shop closed. I have a state trooper that lives around the corner. He has never paid me a visit. Ye I use it to test my ammo.



Link Posted: 3/29/2009 3:25:06 PM EST
Link Posted: 3/29/2009 3:53:07 PM EST
Originally Posted By Flamethrower:
Originally Posted By buzzworm:
I had a gunsmith in a nearby town test fired my rifle outside his shop, in a neighborhood. It was some sort of trap, looked like steel sides, filled with sand, and had what looked like a lid from a 5 gallon bucket on top. The "lid" had a hole in it with what looked like strips of rubber/carpet and he stuck the muzzle in and touched off a round of .308. Very quiet. It sat at about a 45* angle, on some sort of rack to support it. I don't know if he built it, bought it or what. Worked well.


I have this in my workshop. I have since changed the lights over the chrono to incandescent. It's still loud even with the door to the shop closed. I have a state trooper that lives around the corner. He has never paid me a visit. Ye I use it to test my ammo.

http://pic20.picturetrail.com/VOL1293/4220040/21183196/350379246.jpg

http://pic20.picturetrail.com/VOL1293/4220040/21183196/350379352.jpg



I love it!!! I would would have to build something underground to incorporate my chronograph(I have seriously considered it), the snail trap costs wayyy too much and mentions nothing about silence, I guess will have to blaze the trail to a quiet trap. There will be no discussion of legality, we will just assume it needs to remain unheard.

Nothing worse(ok there are much worse things but...) than a range trip paying $10 per gun only to find that there is a function problem with a load or loads so I think I would like to have a convenient, safe and quiet way to make sure my loads work before wasting my time and money on a range trip. The safe and convenient will be the easy part, the quiet will be the hard part considering I have neighbors houses within about 20-30 feet on either side of my house...... Off to Lowes I go....
Link Posted: 3/29/2009 5:29:47 PM EST
2 Plastic 55 gallon drums. Quite a bit of the "egg holder" foam.

If they have lids, remove. Cut a 1" (or smaller) hole on the bottom of one barrel. Put one piece of the foam at the bottom of each barrel cutting a 1" hole in the foam for the barrel with the hole. Wrap some of the foam around the bottom wall of each barrel, but only go about a foot up the side. (spray adhesive or double sided tape works good to hold the foam where you want it) Using the spray adhesive put two pieces of the foam back to back and put half way down each barrel cutting a hole in the middle. (note: on the firing end it is highly recommended that you put some fire retardent spray on the bottom, side and first double foam pads) Wrap some more foam on the walls and add another set of foam facing away from one another.

Duct tape, plastic weld, or use a clamp to hold them together.

For a bullet stop....dirt alway works best, but that is kind of hard to get into the house with a mess. I have used phone books with great success. Was thinking about carpet, just haven't gotten around to trying it out though.
Link Posted: 3/29/2009 7:20:36 PM EST
Link Posted: 3/30/2009 8:18:54 AM EST
Originally Posted By Flamethrower:
I have this in my workshop. I have since changed the lights over the chrono to incandescent. It's still loud even with the door to the shop closed. I have a state trooper that lives around the corner. He has never paid me a visit. Yes I use it to test my ammo.


This is a nice looking set up. Just make sure you have ability to vent gases and dust after firing. Some of this residual may contain lead styphnate.
Link Posted: 3/30/2009 10:59:31 AM EST
Originally Posted By Flamethrower:
Originally Posted By buzzworm:
I had a gunsmith in a nearby town test fired my rifle outside his shop, in a neighborhood. It was some sort of trap, looked like steel sides, filled with sand, and had what looked like a lid from a 5 gallon bucket on top. The "lid" had a hole in it with what looked like strips of rubber/carpet and he stuck the muzzle in and touched off a round of .308. Very quiet. It sat at about a 45* angle, on some sort of rack to support it. I don't know if he built it, bought it or what. Worked well.


I have this in my workshop. I have since changed the lights over the chrono to incandescent. It's still loud even with the door to the shop closed. I have a state trooper that lives around the corner. He has never paid me a visit. Ye I use it to test my ammo.

http://pic20.picturetrail.com/VOL1293/4220040/21183196/350379246.jpg

http://pic20.picturetrail.com/VOL1293/4220040/21183196/350379352.jpg


This seams like a great set up but I imagine if the ends of the sound tube were closed up to a much smaller diameter it would work a lot better at reducing sound. I really want to build a setup like this. It's such a PITA to load up a batch of rounds to test, then wait a week or two till I can make it to the range which is 35min away.

Link Posted: 3/30/2009 11:09:55 AM EST
A remember a story about using tires as an external 'sound' suppressor. Line them (4-6 tires) up on a simple X frame of 2x4's and drill holes in the bottom of the tires to drain water. Fill with rockwool. Insert rifle in a few inches and shoot away.
Link Posted: 3/30/2009 12:47:06 PM EST
Originally Posted By popnfresh:
I hate to waste the time and money on a trip to the range only to find that a load is non functional.


There's mins and maxs for every load. I've never had a "non functional" load. I think you're looking to solve a problem that you don't need to.
Link Posted: 4/2/2009 3:27:10 PM EST
Originally Posted By markm:
Originally Posted By popnfresh:
I hate to waste the time and money on a trip to the range only to find that a load is non functional.


There's mins and maxs for every load. I've never had a "non functional" load. I think you're looking to solve a problem that you don't need to.


A new AR pistol build made me wish I had this thing, tuning my Ciener conversion to work made me wish I had this box, various muzzle devises I have machined made me wish I had this box, loading below minimums made me wish I had this box. I have said "I wish I didn't have to drive to the range just to see if this will work" too many times over the years not to build it........ Although now that I have started, I wish I had not , I doubt I will be able to silence even light handgun rounds enough to make it worth while. One of my main problems is the size limitation which will make it harder to sound absorption/ barrierifying more difficult, I have a small garage that I use for vehicle parking, laundry, and work shop stuff, so I have to keep it narrow.

Here is the start, I plan on firing down through the top(covered with small opening) with the gun completely inside box, I will have a layer of gravel on the bottom then sand and finally a layer of rubber mulch as bullet stop and sound absorbing/ blocking material. All seams will be sealed with 50year silicone, painted inside and out then layered sheets of roofing inside and out all for reducing sound transfer. I will cover the outside with 2X10s most likely to hold it all together, it will weigh a ton I am afraid......



Link Posted: 4/2/2009 5:23:11 PM EST
Link Posted: 4/2/2009 5:51:29 PM EST
My gunsmith uses a 55 gallon drum with the bottom 1/3 filled with sand. It's not that loud, usually. When he test fired my .44 Magnum it was pretty loud though.
Link Posted: 4/2/2009 5:55:24 PM EST
[Last Edit: 4/2/2009 5:56:12 PM EST by NAM]
it won't take more than a hit or two to crack that patio block.....but as long as they keep going straight...you should be ok.
Link Posted: 6/13/2009 6:13:48 PM EST
bump for update
Link Posted: 6/14/2009 5:11:04 AM EST
WOW that is impressive to reduce the sound level, how are you going to empty out the box from the brass and the bullets?
Link Posted: 6/14/2009 9:20:23 AM EST
popnfresh:

Tough crowd, but I like it. To make it really pay off, you should consider a chronograph spool section. Also pick up a garage sale shop vac and rig a PVC pipe induced draft flow system to keep it under negative pressure. Last, make sure you are not drilling a hole in the bucket of sand backstop with successive shots. 155 db down to 95 db is a noise reduction to be proud of.
Link Posted: 6/14/2009 12:23:53 PM EST
Originally Posted By nightwolf357:
WOW that is impressive to reduce the sound level, how are you going to empty out the box from the brass and the bullets?


The brass just lands on the top of the rubber mulch and is easy to pick out. Here is the top view, the tennis balls are to hold the gun in place while I close the lid and to help with sound deadening (they made no difference in sound).


I have been digging out the fired bullets as I shoot, so I fire up to 10 rounds then pull out the balls and start digging out the rubber mulch with a scoop. Only the .223s(the 3 I found anyway) and one of the LaserCast 10mms made it through the 13" to 15" of rubber mulch and about 1"-2" into the sand.

The front row of round nose jacketed are .380autos,..... the 3 lead RNs are 10mm you can see the one that made it to the sand,.... the far TC lead are my castings from the .40, .... the near JHPs are Nosler 135gr from the 10mm,.... the farJHPs are Fed HSTs from the .40,.... behind those are WWB from the .40, .... Look at those 55gr from the AR Pistol! I found them about 2 inches into the sand directly in the line of fire laying flat nearly on top of each other, I couldn't find the other 2, ....in back is all the various .22 rim fires.
Link Posted: 6/14/2009 12:53:38 PM EST
Originally Posted By CCW:
popnfresh:

Tough crowd, but I like it. To make it really pay off, you should consider a chronograph spool section. Also pick up a garage sale shop vac and rig a PVC pipe induced draft flow system to keep it under negative pressure. Last, make sure you are not drilling a hole in the bucket of sand backstop with successive shots. 155 db down to 95 db is a noise reduction to be proud of.


I would love to try to fit my Chrony in but would have to remove a lot of mulch. Everything is air tight to stop sound transfer, the box top and lid mating surfaces are rubber and the hole that I pass my arm through has 2 rubber seals that fit tight at just above my wrist and just below my elbow, air tight is very important and I made sure to seal all seams with acoustic caulk, so any kind of air flow would be detrimental to my sound reduction attempts.

I have about 2" of gravel on top of the concrete, about 18" of sand on top of the gravel and about 13"-15" rubber mulch on top of the sand, the rubber mulch stop just about everything but the .223 which only made it a couple inches into the sand. I think I will be alright a long as I don't try to fire 20 or more rifle rounds into the same spot a one time. The rubber mulch gets repacked after I recover the bullets so the "drill" hole is removed. If something made it through the mulch and sand I would think the gravel would stop it from harming the concrete base. Those blocks on the bottom are a very important foundation to the whole thing so I do want to protect them as they are not made to be replaced.
Link Posted: 6/14/2009 1:02:55 PM EST
Link Posted: 6/14/2009 1:04:32 PM EST
Link Posted: 6/14/2009 4:27:01 PM EST
In the video, what is the distance from the soundmeter to the box, and soundmeter to the hammer ?

Was the meter reading A-weight or C-weight?
Link Posted: 6/15/2009 2:18:03 PM EST
Originally Posted By Shizzlemah:
In the video, what is the distance from the soundmeter to the box, and soundmeter to the hammer ?

Was the meter reading A-weight or C-weight?


The distance from the meter to the box was 10feet, the hammer and 2x4 were at the same distance as the box from the meter. I was at that distance so everything would be captured on the camera. At 1 meter I wouldn't have been able to get the meter, box, and hammer all in the scene. The room with no window coverings, no furniture and concrete floor doesn't do much for sound attenuation so I don't think there would be a great difference in decibel between 4 feet and 10 feet .


I used the C weighting rather than the A weighting that was used in the data from the linked website, I know A is the standard for measuring sound levels as perceived by the human ear, but I believe that to be improper for getting accurate measurements of actual sound pressure levels, C weighting has a flatter response over a broader frequency range, down to 30Hz rather than 500Hz of the A weighting. From what I found in my rimfire testing the A weighting readings averaged 10dB lower than the C weighting readings, so if I would have used the A weighting setting my readings would have been more impressive by 10dB.

My meter was set to C weighting, Fast response and set to show "Max" reading which is measured over a 1 second time period. Like I stated in my updated post, the meter is for comparing measurments that my meter took, compare the hammer strike to the shots fired and to compare the different calibers, the data provided from the webpage is for a rough reference . My meter wont read more than 126dB so I couldn't give a measurement of my actual guns and loads.
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