Why would one want sub-sonic loads?

[stev32k]

I occasionally see references to sub-sonic loads and wonder exactly what they are and why anyone would want them? I assume "sub-sonic" means a velocity less than the speed of sound - 1,126 ft/sec. Most (maybe all) of the pistol cartridges I plan to load have velocities below that, but why is that important - or is it important?

[DeeDubya]

Suppressors will only perform well with sub-sonic ammo as they can reduce the muzzle blast but not the crack of a supersonic bullet.

Also, I have read that for optimum accuracy it is best to not be right at the speed of sound because of slight velocity variations some bullets will be subsonic and some will be supersonic. They claim that if a bullet starts supersonic and then slows to subsonic during flight it becomes unstable at that point. Personally I have not been able to witness this because I load a lot of 40sw right at 1100 fps.

[carver]

If I haven't welcomed either of you two guys to the forum, let me do so now. Steve, you got a good answer to your question. Also, what if you had a .357, or .44 magnum lever gun, and wanted to shoot lead bullets in that rifle? If you don't know exactly how hard that lead bullet is, then any thing that is not subonic may lead the barrel of your rifle.

[cycloneman]

My resoning is simple. When the shtf and there is total lawlessness then you may need sub sonic ammo for various reasons. At that time you can improvise a device to make your noise signature low, out of anything, like a 2 litter bottle that is disposible. The ss ammo would allow you to say hunt at night when you dont want neighbors to here you. Low noise ammo in 22 is great for birds that will make a pot of stew.

SS ammo use is only limited to your imagination.

[Willie]

Originally Posted by cycloneman

My resoning is simple. When the shtf and there is total lawlessness then you may need sub sonic ammo for various reasons. At that time you can improvise a device to make your noise signature low, out of anything, like a 2 litter bottle that is disposible. The ss ammo would allow you to say hunt at night when you dont want neighbors to here you. Low noise ammo in 22 is great for birds that will make a pot of stew.

SS ammo use is only limited to your imagination.

Quite right. I live in the "city" on two acres and have chickens. I use subs to shoot predators. They are harder to hear than my pellet gun. Just hear the click. Coons,possums etc die quickly and quietly. Sometimes when shooting a flying predator you can even see the lead flying in air. Takes some practice but I am deadly with them and nobody hears a thing.

[Zhurh]

Is that 300 Whisper sub sonic? Would be nice to have one gun for a specific purpose; like noise suppression.

[Maine04657]

Originally Posted by DeeDubya

Suppressors will only perform well with sub-sonic ammo as they can reduce the muzzle blast but not the crack of a supersonic bullet.

Half true. The objectives for suppressors are two fold one to be SILENT and one to be HEARING SAFE. The former being harder to achieve but very doable. The latter to remain hearing safe is easily done with hypersonic ammo. As the sonic boom occurs away form he firearm. So let us say you have a .308 bolt rifle with a decent suppressor the noise from the sonic crack will remain but the shooter will hear very little noise and be able to shoot all day with NO hearing protection and have there ears remain free from damage. To take the .308 further we can use a subsonic round thus removing the crack and bringing the total noise level WAY down with the right load you woudl hear nothing more then a very small pop. The wildcat folks work hard to get the best load power vs silence ratio thus the 300 blackout.

Here is my 10/22 integral shooting subs at steel targets 30 years away. You hear the click of the action and the bullet hitting the steel but not much else.. http://youtu.be/VwXQYln0Zc8

[Alpo]

Some of the nonsense people put on the internet is amazing.

The speed of sound is right around 1100 fps. So if your load is slower than that, it is subsonic.

What falls in that range?

38 S&W. 38 Special. 380. 9mm Mak. 44 Russian. 44 Special. 45 ACP 45 Colt.

Every one of them is subsonic. And they are quieter than a pellet gun? And you can see the bullet in flight?

[stev32k]

Originally Posted by Maine04657

Half true. The objectives for suppressors are two fold one to be SILENT and one to be HEARING SAFE. The former being harder to achieve but very doable. The latter to remain hearing safe is easily done with hypersonic ammo. As the sonic boom occurs away form he firearm. So let us say you have a .308 bolt rifle with a decent suppressor the noise from the sonic crack will remain but the shooter will hear very little noise and be able to shoot all day with NO hearing protection and have there ears remain free from damage. To take the .308 further we can use a subsonic round thus removing the crack and bringing the total noise level WAY down with the right load you woudl hear nothing more then a very small pop. The wildcat folks work hard to get the best load power vs silence ratio thus the 300 blackout.

Here is my 10/22 integral shooting subs at steel targets 30 years away. You hear the click of the action and the bullet hitting the steel but not much else.. http://youtu.be/VwXQYln0Zc8

I watched the video and the noise level is pretty impressive. What kind of ammo where you shooting?

[bamajoey]

CCI Quiet (710 FPS) makes very little sound out of the 24 in barrel of a CZ 452 LUX.

[al45lc]

My "why" is simple, in the .22 rimfire the noise level is low enough so as not to disturb the other game in the area, especially the squirrels I'm hunting.
The Remington Sub-Sonic is very accurate too, and great lethality.
Why go 'sneaking' around the woods just to disturb it all with a sharp 'crack'?