Big game (Elk, Deer) with subsonic ammo?

Problem with the whisper series those are proprietary cartridges made from really expensive brass. For your project I would look into a .50 Alaskan, nice round for regular hunting, and as a rimmed round you can shorten it to fit the larger bullets on it. Should sill have plenty of powder space to reach those 1200 ft/s you need.
 
Problem with the whisper series those are proprietary cartridges made from really expensive brass. For your project I would look into a .50 Alaskan, nice round for regular hunting, and as a rimmed round you can shorten it to fit the larger bullets on it. Should sill have plenty of powder space to reach those 1200 ft/s you need.
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That is a good idea but is there any way to put a 50 AK with a big (50BMG) bullet in a repeater or would I be limited to a single shot or a double rifle?
 
At the risk of being a preachy wet blanket type, keep in mind that there are many, many things that can be done in life, but shouldn't be. Theoretical situations are instructional and interesting, but this is one of those ideas that would be best to leave on the napkin.
 
To me it sounds like fun. As stated before I am working on a suppressed 45/70. I plan to use regular hunting loads in it.

I would suggest to the OP to try to hunt this year with the subsonic loads and see how it goes even though he probably will not have the suppressor yet, even if he put the paper work in today. If you can take game with this load with out a suppressor then adding the suppressor will not change any thing other than having to adjust the sights slightly.

Many people frown on suppressors for hunting but I think they are great. Just be prepaired to get stopped. I find many officers to not know much about civilian ownership of suppressors. This is second hand information but I believe it.

p.s. If hunting in Idaho make sure your gun is not heavy. If the gun is even 1 oz heavier than 16LBS you can not use it in Idaho for hunting and you may have to do more than just pay a fine, you could loose the gun and your hunting rights.
 
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amflyer said:
At the risk of being a preachy wet blanket type, keep in mind that there are many, many things that can be done in life, but shouldn't be. Theoretical situations are instructional and interesting, but this is one of those ideas that would be best to leave on the napkin.
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The idea that you can't hunt big game with subsonic ammo is beyond laughable.

10s of thousands of hunters kill animals all over the world with 300-400gr projectiles at 200-300 fps on a daily basis.

All over the world, big bore air guns (YES, AIR GUNS!) are and have been used on big game for at least 2 centuries. Big bore air guns were, for many years, the most powerful "fire"arms available.

It's not an ethics question, it's a logistics question. There are plenty of entirely suitable options.
 
I would consider a .338 Whisper. Long, heavy, aerodynamic bullets will mandate a fast twist at 1050-1100 fps, probably 1 in 7" to stabilize properly.
 
That is a good idea but is there any way to put a 50 AK with a big (50BMG) bullet in a repeater or would I be limited to a single shot or a double rifle?
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That's why I mentioned you can probably cut back the case a bit to keep the OAL the same; the cartridge headspaces on the rim, and the case is nearly cylindrical from what I can tell.
 
Art Eatman said:
And remember, the higher the elevation, the slower the speed of sound. At 5,000 ft, sub-sonic is around 1,050 ft/sec.
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Actually, it's the temperature of the air, not its atmospheric pressure that determines the speed of sound and air does get colder at high altitudes so your statement is true in an indirect way.
But, if you are on top of a 5000 ft mountain and the air temperature is 80 degrees F, the speed of sound will be the same as it is in 80 degree sea level air.
Ammo that was subsonic during the hot summer may become supersonic during that winter cold snap.
 
B.L.E. I won't argue, but my comment derived from a website set up to calculate Mach numbers at various altitudes; temperatures could be included, of course, but air density varies with altitude alone, regardless of temperature.
 
Actually, it's the temperature of the air, not its atmospheric pressure that determines the speed of sound and air does get colder at high altitudes so your statement is true in an indirect way.
But, if you are on top of a 5000 ft mountain and the air temperature is 80 degrees F, the speed of sound will be the same as it is in 80 degree sea level air.
Ammo that was subsonic during the hot summer may become supersonic during that winter cold snap.
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You know, I wasn't a physics major or anyhting but I don't believe that is correct.

Density is the name of the game when dictating how fast waves can move through a substance...sure tempature has an effect on density, but density and and not temp will dictate the speed of said waves.

For expample, in water which...far more dense then air the speed of sound is much faster. Through rock is even faster then that.


Of course I could be completely wrong... but thats the way I understand it.
 
Density and pressure of gases are not independent from each other (ideal gas law works pretty decent for the atmospheric gas mixture), and their contribution cancels itself out. Speed of sounds rises with the square root of absolute temperature for a given gas mixture.
 
The speed of sound through a fluid is the square root of (bulk modulus/density).

Bulk modulus is a fancy name for how stiffly it resists compression. As you go up in altitude, both the force needed to compress the air and the density go down together, resulting in a constant speed of sound.

Increasing the temperature lowers the air's density without also reducing its bulk modulus so heating the air results in an increase in the speed of sound.

The reason the speed of sound in water is so high is because it has an extremely high bulk modulus, i.e. it's nearly incompressible.

If you look at speed of sound vs altitude charts, look at altitudes higher than 40,000 ft. At these altitudes, the air no longer gets colder with an increase in altitude and the speed of sound stops decreasing.
 
"...At these altitudes, the air no longer gets colder with an increase in altitude..."

Now, that'll warm the cockles of an astronaut's heart! :D

The denser the medium, the faster that sound waves travel. Less dense = slower travel. Increasing altitude = lower air density => lower speed of sound.
 
The denser the medium, the faster that sound waves travel. Less dense = slower travel. Increasing altitude = lower air density => lower speed of sound.
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It's not that simple.
Consider the following.
The speed of sound in:
hydrogen at 0 C 4219 fps
helium at 0 C 3189 fps
air at 0 C 1085 fps
air at 20 C 1125 fps

Notice a trend?, the less dense the gas, the faster the speed of sound.
Lighter gasses have less momentum so when compressed, they can spring back to original volume faster and that makes sound waves travel faster.
Harder to compress gasses also spring back to original volume faster so gasses that are harder to compress have a higher speed of sound.

At high altitudes, the air is less dense, which speeds up the speed of sound, however, less dense air is easier to compress, which slows down the speed of sound. The two cancel each other out.

Check out this link and look at the temperature and speed of sound at altitudes above 35000 ft. This chart goes to 60,000 ft and I guarantee that the air density at that altitude is less than at 35,000 ft. Above 35,000 ft, the air stops getting colder and the speed of sound becomes constant.

http://www.fighter-planes.com/jetmach1.htm
 
Did you know that the speed of sound is completely irrelevant to killing an animal?

Yep. Sure is. The only reason anything about air matters at all is if you pop the big air bags inside the animal, they die. They don't care how fast the projectile is going or what Mach is. They only care that they can't breathe.
 
It would have to be one heavy bullet to be legal in CO. To be legal for big game in CO with a centerfire rifle you have to use a minimum of a 6mm or larger caliber bullet 70 grain minimum for deer, black bear, and pronghorn, and 85 grain minimum for elk and moose. Plus it has to generate a minimum of 1000 ft lbs of energy at 100 yards.

Easiest way to get around the regulations in Colorado is to hunt muzzle loader if you want subsonic but I'm pretty sure it would look funny with a "can" threaded on the end of the barrel. ;)
 
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It would have to be one heavy bullet to be legal in CO. To be legal for big game in CO with a centerfore rifle you have to use a minimum of a 6mm or larger caliber bullet 70 grain minimum for deer, black bear, and pronghorn, and 85 grain minimum for elk and moose. Plus it has to generate a minimum of 1000 ft lbs of energy at 100 yards.

Easiest way to get around the regulations in Colorado is to hunt muzzle loader if you want subsonic but I'm pretty sure it would look funny with a "can" threaded on the end of the barrel.
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I think most rounds of 500 grain rounds or heavier will pull off 1000FP at 100 yards if loaded to 1050 at the muzzle.
 
500 grain loads out of a .50 won't do it at 1050 fps, you'll have about 980 ft-lbs of energy at 100 yards. .338 or .30 calibers would be the most economical way to do it, but they will lack adequate energy for use on elk. Doesn't mean it won't kill them, just that the OP better be close and hone his tracking skills. Plus I think a bullet made/cast of soft lead will perform better than a jacketed rifle bullet, that is why I suggested a muzzle loader.
 
50-70-750

I have an SSK barrel for my T/C Encore 1-8" twist. I load 647gr. BMG bullets into 50-70 cases. They come out at about 950fps and are quite accurate out to 200 yards. At 200 yds they are still going 870 fps and have 1100 ft.lbs of energy remaining.
Note: some years ago, there was an article in "The Double Gun and Single Shot Journal" by Ross Seyfried in which he describes an elk hunt on which he used a single shot rifle chambered for the .455 Webley. *
Pete *
 
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