Thread: Quietest firearm possible?

I've been thinking, what would be the quietest you could make a firearm, just for fun? I've been toying with the idea of getting a pistol calibre carbine of some sort for a while now, mainly for small game, but also to suppress and play around with subsonic loads. I'm guessing some of the quietest rifles ever were the De Lisle carbines; owing to it being manually operated, using subsonic ammo, and the over-sized suppressor. But does anyone know if having a ported barrel bleed gas into an integrated suppressor would make it quieter if the projectile was already subsonic to start with? Does anyone know the lowest velocity you can load an still have the projectile exit the barrel each time reliably, I'm assuming the slower; the less noise. Also, would cast lead bullets be quieter than jacketed ones? What about the firing mechanism; it seems like the loudest part of firing the De Lisle, would an external hammer like on a break-barrel or lever action be any different than a firing pin inside a bolt action? Are all cartridges created equal for subsonic loads or are some just inherently good? I don't really want to get into wild-catting but I know the Russians have a cartridge that is essentially a 7.62x39 necked up to 9mm for launching heavy bullets sneakily. Right now I'm thinking of picking up a cheap single shot break barrel (for safety so I can check bullets are not stuck in the barrel after each shot) in .44 magnum or similar, sticking a maximus suppressor on in and loading some subsonic rounds using Trail Boss. Does anyone have any ideas?

My brother has a break barrel suppressed .44 magnum. It is very quite, making more of a popping sound than anything else. The round hitting the target is just as loud as the pop at the shooter end.

I would highly recommend a H&R .44 mag with a Gunworks Maximus suppressor and sub sonics with Hornady 240 grain XTPs if you are wanting to shoot decent sized animals at reasonably close range.
Shorten the barrel up until its still just legal for length and fit suppressor to that.
You don't need much barrel length to get subs up to speed even with Trailboss powder and cases will last a lifetime !
Don't try to go too slow for noise or sooner or later one will stick in the barrel !
Load up until you break the speed of sound ( do load work without ear protection ) and then go back down to your previous quiet and accurate load.
The 240 XTPs are very accurate in my rifle exactly as above.
I tried the 300 grain XTPs but they don't stabilize and also the 240s penetrate and expand more reliably on big animals.
For shooting pests you can still use copper washed / hard cast el cheapo projectiles and the accuracy is OK.
Be aware that the projectiles will exit ever thing you shoot at and can be heard zipping off into the distance so be especially careful when shooting possums up trees.

It helps to have a decent gun dog to trail animals if you intend shooting deer, goats or pigs with them as they aren't flattened on the spot.
Just treat it like bow shooting ( if you don't see them drop ) , wait a short while and then trail slowly with the dog and they will usually have stopped and bled out fairly quickly.

I have a lot of .44 sub testing with trailboss on a sheet if you want it.

A 22 bolt action rifle launching subsonic bullets in a very long barrel with a very long suppressor is the quietest you would get.
The bigger the exit hole the more noise it makes.
The heavier the projectile you launch, the more powder you need, the more gases it produces, the more noise it makes.

These are the rules.

We have set up a couple Baikal 7.62x39s for sub loads. We used a Gunworks suppressor that is made for that purpose and cast bullets (sometimes with gas checks depending on what velocities you are chasing- Anything over 1100 fps is where we start to use them. At about 1300fps from memory, the lead melts into gobs of metal spittle without them. ) .

Pistol calibres should work well too.

During WW2 the brits developed a Lee Enfield variant called the De Lisle carbine which was SMLE MkIII in .45ACP with a Thompson Barrel and a M1911 magazines, it had 2 inch wide supressor and was apparently silent with Subs. I saw somebody on TM doing their own version in 44 Mag about 2 months ago.

what Tim has shown above would be my choice hands down..... all the hard work is already done. running a 151grn hp cast projectile off trademe powered by around 7grns of trail boss is QUIETER than a long barrelled norinco .22 with suppressor (even a big one) Im using a GW Spartan can on the x39mm
Ive shot bunnies with it and its mates don't move unless you cycle the bolt,or mate shoots next one with .22 LOL.
as said above be VERY aware of background as subsonics whizz off into distance rather alarmingly .

I've got a deLisle replica in the standard 45cal configuration and it is about as loud as bouncing a soccer ball hard off wet asphalt from shoulder height.
Apparently people have done all sorts with them like putting oil in the suppressors and stuff but I've kept it standard
The bullet drops like a stone though

Welcome to try it if you are in Welly - pm me

I've seen videos of 300 Blackout in an AR15 config with suppressors sounding about as loud as a stapler

Yep I see there is a De Lisle reproduction on trademe at the moment, but they want $2000 for it.... I have a Baikal 7.62x39 and it shares the can on my .308, it is quiet with subsonic loads but not as quiet as some of the .22's i've handled, I think @Friwi must be right, my mate has a Marlin XT22 with a suppressor and it make less noise than an air rifle. Maybe i'll stick with the 7.62x39, I've been using 150 grain Sierra .311 Pro Hunters with 7 grains of Trail Boss, are cast bullets worth trying?

Originally Posted by 308

I've got a deLisle replica in the standard 45cal configuration and it is about as loud as bouncing a soccer ball hard off wet asphalt from shoulder height.
Apparently people have done all sorts with them like putting oil in the suppressors and stuff but I've kept it standard
The bullet drops like a stone though

Welcome to try it if you are in Welly - pm me

I've seen videos of 300 Blackout in an AR15 config with suppressors sounding about as loud as a stapler

But you still get a bit of noise with the bolt slapping back and forth on an AR; I reckon there's probably a market for straight-pull or pump-action uppers in .300 Blackout

There is a JP silent captured buffer spring available for Ar's to quieten the air-rifle like twang of buffer, supposed to be good but a little pricey if purchased here like everything else.
Troy Defense make a pump-action in 300AAC based largely on an Ar configuration with a folding stock, but NZ Police have made importers pin the folding stock. They look quite nicely made.

Originally Posted by tommygun

But you still get a bit of noise with the bolt slapping back and forth on an AR; I reckon there's probably a market for straight-pull or pump-action uppers in .300 Blackout

Troy PAR 300 blackout | Trade Me

And they aren't dear either

My experience with fully suppressed rifles tells me the porting of the barrel does make a huge difference.
I own an over barrel suppressed jw 105, over barrel suppressed 10/22 and a mate had a savage Shorty. The Shorty is very similar to the jw, I'd say the jw is a very good copy of the savage. The savage is fully suppressed which included the barrel porting and it is notably quieter than the jw. The 10/22 had a barrel sound the same as the jw but is notably louder due to the action noise even with an after market polymer buffer.
When it comes to ammo, the higher the grains the louder the noise. I shoot Winchester in all, the 36gr are much quieter than the 40gr and 42 gr. I'm not sure of the exact science why but that is the results of comparing side by side.
The savage easily came out the quietest but it also had the slowest projectile.

Sent from my workbench

And I must add that the first shot I fired with the savage I thought it had miss fired

Sent from my workbench

Cz455 with a small suppressor on it from @perriscuba is incredibly quiet running cci subs, makes my 10/22 sound like a cannon