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SevenRoundMags
December 1, 2005, 11:39 PM
Just want to clarify: The noise a gun makes when being "fired" is due to the bullet creating a seal around the gases propelling it. When the seal finally breaks (bullet leaves barrel) the loud popping noise is head- similar to a champagne bottle being opened. Sound about right?

thanks.

mtnboomer
December 2, 2005, 12:18 AM
Yes, that's the biggest part, but not all of it. If the bullet goes hypersonic then after the bullet leaves the barrel it passes the speed of sound and there will be a "sonic boom" - the sharp, high-pitched "crack" you hear which makes your ears ring if you're not wearing hearing protection.

BTW - The roar you hear from the muzzle flash when the bullet leaves the barrel isn't unburnt powder burning. It is the super-heated gases created by the burning powder [which have already completely burned before the bullet exits the muzzle] cutting a hole in the atmosphere by burning the oxygen at the point of the blast and then the atmosphere slamming closed to fill the void. Similar to the way lightning creates thunder. The bigger the muzzle blast, the bigger the bang! ;)

gdeal
December 2, 2005, 12:21 AM
Science & Physics on The Firing Line Forum. Who would have thought?

Mikeyboy
December 2, 2005, 08:37 AM
That is why a silencer works. It baffles and muffles the escaping gases just like a muffler on the car quiets the tailpipe exhaust. If you ever lost a muffler while driving, it sound like your driving an old tank.

Weeg
December 2, 2005, 08:48 AM
Don't forget the "Crack" (sonic boom) of a rifle muzzle.


?

BlueTrain
December 2, 2005, 08:52 AM
There is more. It has sometimes appeared to me that the sound of an unexpected gunshot (nearby) is perceived as little more than a popping sound, while an expected shot sounds louder, if you follow me. That is something that is very hard to quantify and not very easy to explain in a convincing way either. It is a little like cutting yourself accidentally and not realizing it until you see the blood.

Muzzle blast, on the other hand, is also difficult to define in a neat and pat way but clearly it exists, though only noticable in larger calibers. A .22 rifle is supersonic but no one would claim there is any muzzle blast in the usual sense of the expression. Most .357 magnum loads certainly produce muzzle blast, although it may be most noticeable at indoor ranges. You should see the muzzle blast from artillery being fired.

There is some confusion and probably controversy about gunpowder being burned entirely within the barrel of a gun, usually spoken of handguns. If all the powder is consumed within the barrel, which probably would happen with a faster burning powder like Bullseye, it doesn't not follow that the greatest velocity will be achieved. Heavier charges of slower burning powders may produce a higher velocity in spite of less than complete burning, either inside the barrel or at all. There is more to it than that but you get the idea.

Muzzle flash can be confused with muzzle blast but I use the term to mean visible light at the front end when the gun is fired. Some cartridges have a reputation of a lot of that and the 7.63 Mauser (handgun) and Tokarev are good examples. Overall, however, it is a characteristic of different powders and I understand that there are additives to commercial loads for the purpose of reducing muzzle flash. American military ammunition is supposedly good in this respect, though I have seen only a few references to the topic.

In any case, I wonder is shooting guns has caused the ringing in my ears?

MidKnight
December 2, 2005, 05:47 PM
If the bullet goes hypersonic

If memory serves me, "hypersonic" is above mach 5 or 5 times the speed of sound. Supersonic is mach 1 thru 5.

/sorry, I'm a nerd.