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.

Originally Posted by timattalon

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.

For what its worth, this rig brand new will set you back $900 including shipping. That is rifle, threading, suppressor and red dot scope and freight. And I have one left.

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 .

Originally Posted by Micky Duck

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 .

Originally Posted by tommygun

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?

With the cast bullets in 303 cal (7.62x39 is the same as 303 rather than 7.62x51 which in same as 308) the 180gr and 220gr cast with or without gas check hold their energy a bit further than the 150s. They still rise and fall at the same rate as the 150s as long as they are doing the same speed. Definitely worth trying as they are far cheaper than using copper jacketed bullets and at the lower speeds the softer lead seems to mushroom better than the ones designed for higher speeds. (Though deform is probably a better word than mushroom.) You do need just a grain or so more of the trail boss to get the same 1000 fps to stay subsonic. Projectils are around 8 or 9 cents each when you start making your own.....add a 10c primer, and a few cents worth of powder and it makes for cheap shooting too, not that this is the aim of said project...

One advantage of the break open rifles is overall length is not an issue as it is when feeding from a magazine. So the 220gr will fit no matter how long it is.

Unless your shooting gongs or targets,Holding energy in that upper range of weight is useless. A .30 cal 150 gr HP cast lead bullet at subsonic speeds travels through two goats standing next to each others( experienced it 3 different times at 30m, 90 m and 156 m!) so any more weight on your projectile is unproductive. ( inless you want to shoot through 4 or 5 goats standing next to each other's, good luck, you may as well play the lotto).
Because you are adding more powder you generate more noise. And in some cases, the rifling twist used for stabilising normal bullets at supersonic speeds is not fast enough to stabilise heavier bullets at subsonic speeds, so you can loose on accuracy.

Cast bullets are definitely cheaper than the jacketed bullets, but I have yet to see a cast projectile shooting as accuratly as some jacketed projectiles do at subsonic speeds.

Originally Posted by Friwi

Unless your shooting gongs or targets,Holding energy in that upper range of weight is useless. A .30 cal 150 gr HP cast lead bullet at subsonic speeds travels through two goats standing next to each others( experienced it 3 different times at 30m, 90 m and 156 m!) so any more weight on your projectile is unproductive. ( inless you want to shoot through 4 or 5 goats standing next to each other's, good luck, you may as well play the lotto).
Because you are adding more powder you generate more noise. And in some cases, the rifling twist used for stabilising normal bullets at supersonic speeds is not fast enough to stabilise heavier bullets at subsonic speeds, so you can loose on accuracy.

Cast bullets are definitely cheaper than the jacketed bullets, but I have yet to see a cast projectile shooting as accurately as some jacketed projectiles do at subsonic speeds.

Thinner skinned animals and I am inclined to agree. It is like buying faster 22LR. In most cases subs (22) will go straight through a rabbit and a super just goes through faster. But with more stubborn animals I have found the bigger bullets more like hitting it with a bigger hammer.

When trying to remain subsonic, the only limit is speed. So to carry more energy further you need more weight. If you have sufficient energy then more weight is not needed. A 150gr traveling at the same speed as a 220gr will not carry the same energy. I used the Hornady ballistic calculator and by pushing it all the way out to 250 yards (way more than I would ever use a sub 30cal) I found the trajectory difference is negligible, velocity difference is remarkably closer than I expected as well, but energy retained remains considerably higher on the heavier bullet as to be expected. As mentioned, on soft game like goats this is not really a problem, but on heavier set game like a sturdy bush stag or ornery boar, I think I would go for the heavier bullet. For penetration in these cases a copper jacketed "normal" projectile would work but so too would a harder compound lead. With lead you can control the amount of softness so it mushrooms / distorts quickly (soft) or holds its shape for penetration (hard).

All will work, and whatever you decide you want to use then the beauty of handloading is you can load exactly what you prefer. For subs I prefer a large 220gr at around 1000fps and from what I have seen it works "up close and personal" in scrub. You are also correct that accuracy is still key and if you are having success with 150s then a 150 that hits its target will be more effective than any 220 that misses.

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

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

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

Originally Posted by Tommy

Troy PAR 300 blackout | Trade Me

And they aren't dear either

I've seen them but I didn't think the upper could be swapped with a regular AR one? I assumed the police wouldn't have approved them for import if you could take the upper off an A cat semi-auto AR and put it on the pistol-grip, big mag lower on the Troy and have an un-registered E cat.