Rifle Report Reduction - Noise Box

[Killer Spade 13]

A question for all of you basement engineers out there . . .
Have any of you ever built, or considered building a box with sound dampeners in it through which to shoot to reduce the amount of apparent report generated by the rifle?

In deference to my neighbors, I've considered making a plywood box and lining it with sound absorbing material to reduce the amount of noise pollution generated at our little range.

The box would be about 18"x18"x36" and lined with an acoustic foam material or something similar.

Any input, advice or observations?

Thanx . . .

 

[LoneWolfUSMC]

Re: Rifle Report Reduction - Noise Box

Big volume on the box, small aperatures for the muzzle to enter and the bullet to leave. Its just like a massive silencer.

The principal is sound the construction methods will determine the effectiveness. If I was shooting in a shop, I might give one a try. It wouldn't support the type of shooting I do now though.

 

[Trevor]

Re: Rifle Report Reduction - Noise Box

I have heard of people putting together 4-5-6 tires and using it as a sound moderator

 

[HPLLC]

Re: Rifle Report Reduction - Noise Box

It will be a major pain in the butt to make anything that works well, and it will probably be louder for you unless you're end has a very small hole.

A sound suppressor is the ideal solution to the problem- as it replaces multiple large objects and a one direction keyhole, with a mobile device capable of shooting anywhere you point the weapon.

If I had to make one, I would probably want to try something like 7 2" open cell foam lined floor and walls 2x2 foot boxes with an 8" hole in each side. The one closest to the firer would have plexiglass with a small 1.5" hole for the muzzle.

That seems like it would be a lot of work.

An old Connex box would be sweet. You could weld two steel walls in the middle, cut out a 1 foot window with a plasma cutter and go to town.

 

[RollingThunder51]

Re: Rifle Report Reduction - Noise Box

Hang on, some folks here at the hide have built some fantastic stationary "deflectors" they welded them up and caught the concussion right at either side of the brake and then piped it up and forward...Why didn't I keep those pics?!? Stupid stupid stupid....

Post this question out on the "1000 yard" thread...I remember it being for a .408.

 

[BobinNC]

Re: Rifle Report Reduction - Noise Box

 

[Killer Spade 13]

Re: Rifle Report Reduction - Noise Box

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BobinNC</div><div class="ubbcode-body">

</div></div>

Bob, that's pretty much what I had in mind. How did does it work?

 

[TexIndian]

Re: Rifle Report Reduction - Noise Box

I saw an article once where a guy shooting out of his barn/reload area (lucky sumbitch) made a giant suppressor by cutting holes in the ends of a couple 55 gal barrels welded together and cramming the outer rings with metal shavings from a machine shop. He had the barrel assembly on wheels so he could roll it out of the way when it wasn't being used.

 

[lroseen]

Re: Rifle Report Reduction - Noise Box

I love the idea, I was going to build something like this for my Dad after reading it. I assumed that since it doesn't attach to the rifle it would be a way around nfa laws and rules. However I found that in MN where my Dad lives legally anything designed to reduce or dampen the noise signature of a firearm is considered a silencer. I only bring this up so that those that do build are careful and don't get yourself in trouble.

 

[Killer Spade 13]

Re: Rifle Report Reduction - Noise Box

So, would that include enclosing your shooting hut and firing through a hole in the wall????

I know this is a bit of hyperbole, but it still begs the question.

 

[lroseen]

Re: Rifle Report Reduction - Noise Box

No, because at your muzzle, outside your "shooting hut" the sound would remain the same volume. You would not decrease the actual report of the rifle. Also I was only commenting on Minnesota since I was considering making one of these boxes for my father. I may still make one for myself as I live in Montana and so far I can't find anything that would make this illegal here, so check your states gun laws.

The other question you may want to look up with this "hyperbole" is if it is legal to shoot from a permanent structure in your state. Some states specifically have laws against discharging firearms in residences or buildings.

 

[Killer Spade 13]

Re: Rifle Report Reduction - Noise Box

Geezzz, MN sharpshooter, why don't they just leave us alone.
Ya try to be nice to yer neighbors and they want to put ya in the stoney-lonesome . . .

. . . damned if ya do, damned if ya don't!!!!

 

[cwshooter]

Re: Rifle Report Reduction - Noise Box

I'd be wary of foam. You're going to have a large ammount of very fine soot/carbon dust/ unburned powder accumulate.
I know of one shooting range fire locally, where their dust-empregnated foam went up like a torch. I'd heard the Glock facility had the same occurance back in 03.
I like the tire idea as well. I imagine it would be pretty easy to put plywood end-caps, and perhaps and intermediate baffle or two.
CW

 

[Killer Spade 13]

Re: Rifle Report Reduction - Noise Box

Yeah, the tire configuration looks quite doable . . .

 

[Tripwire]

Re: Rifle Report Reduction - Noise Box

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Killer Spade 13</div><div class="ubbcode-body">Yeah, the tire configuration looks quite doable . . . </div></div>

Use, say 15" or 16" tires, all the same size, for ease of construction.

Bolt them together at the "bead", 3 or 4 bolts each is plenty.

Run a bead of silicone caulk around the tires where they join together, to keep rain water from seeping in and filling your tires on the bottom.

Stuff the insides of the tires with Pink Panther.

Construct a "tube" of small hole chicken wire, that fits snugly inside the length of the project to keep the Pink Panther in place.

Make a plywood plug with a just big enough window to shoot through, hinge a trap door cover for this window that folds down.

Make a solid plywood plug for the other end; both the trap door cover and this second plug are in place when not in use to keeps da critters/birds out of your Pink Panther.

If/when the insulation gets nasty, just replace it.......

If you are worried about a possible fire, keep an extinguisher handy......

 

[The Mechanic]

Re: Rifle Report Reduction - Noise Box

 

[Killer Spade 13]

Re: Rifle Report Reduction - Noise Box

Mechanic,

Now that's just BAD ASSED Rube Goldberg!!!

You win, buddy, you win !!!

You really deserve some sort of Sniper's Hide award/trophy for that one!!!!!

By the way, are those headers tuned??? If you get them ceramic coated you'll pick up 15 fps!!!!

By the way, love the Ford.

 

[Nocalphoenix]

Re: Rifle Report Reduction - Noise Box

I saw photos from the 1980s of the IRA built covert rifle ranges using the tire set up. IIRC they had some 20-30' long with rubber conveyor belting at the ends with slots cut in them. They were very effective and tough to locate unless you had a snich to show the way.

 

[AED146]

Re: Rifle Report Reduction - Noise Box

i guess as long as it does not attach to the gun its legal ???

 

[AED146]

Re: Rifle Report Reduction - Noise Box

How many feet past the barrel does the bullet hit the sound barrier to make the crack sound?

 

[bohem]

Re: Rifle Report Reduction - Noise Box

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mike#9</div><div class="ubbcode-body">How many feet past the barrel does the bullet hit the sound barrier to make the crack sound? </div></div>

The bullet is past the sound barrier for ambient air pressure around 4" down the barrel in a rifle.

The next time is sees the sound barrier depends on the bullet's BC and muzzle velocity but anywhere from 100yd (in 22LR) to a couple thousand yards.

Everything in between has a "crack".

 

[JeffP40]

Re: Rifle Report Reduction - Noise Box

Never saw a rifle with stacks before!