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M
mukwah
Guest
Re: What does "Keyhole" Mean
I think it means turned sideways. Don' t know what causes this though.
I think it means turned sideways. Don' t know what causes this though.
Re: What does "Keyhole" Mean
Yes thats right.....The bullet can tumble and therefore makes a hole in the paper that looks like a keyhole......
This is normally not good.....But the M16 was designed to do this for more damage to flesh and bone....
Type of bullet makes a big difference....some bullets stabilize better and make a nice round hole in the M16 targets....
Some of my pistol bullets will tumble if not loaded correctly.....
Yes thats right.....The bullet can tumble and therefore makes a hole in the paper that looks like a keyhole......
This is normally not good.....But the M16 was designed to do this for more damage to flesh and bone....
Type of bullet makes a big difference....some bullets stabilize better and make a nice round hole in the M16 targets....
Some of my pistol bullets will tumble if not loaded correctly.....
It's true that "keyhole" refers to the oblong hole made by a bullet that has tumbled in flight.
What's not true, however, is the concept that the M16 and its 5.56x45 cartridge were designed to make the bullet tumble in flight. In fact, quite the opposite is true. The M16 and its ammunition is designed to be accurate out to several hundred yards. If the bullet tumbled in flight, this accuracy would be impossible to achieve.
What does happen with the bullets fired by an M16, though, is tumbling after it has entered the mass of a combat target (not a paper target, though). This is because of a combination of the high velocity (typically near 3000 feet per second at the muzzle even from a carbine) and the fact that the bulk of the mass of the bullet is at the rear of the bullet causing it to upset in a target like a human's body. Often, this tumbling in a target will lead to a breakup of the bullet and that causes significantly more wounding of the target than if the bullet went straight through it.
What's not true, however, is the concept that the M16 and its 5.56x45 cartridge were designed to make the bullet tumble in flight. In fact, quite the opposite is true. The M16 and its ammunition is designed to be accurate out to several hundred yards. If the bullet tumbled in flight, this accuracy would be impossible to achieve.
What does happen with the bullets fired by an M16, though, is tumbling after it has entered the mass of a combat target (not a paper target, though). This is because of a combination of the high velocity (typically near 3000 feet per second at the muzzle even from a carbine) and the fact that the bulk of the mass of the bullet is at the rear of the bullet causing it to upset in a target like a human's body. Often, this tumbling in a target will lead to a breakup of the bullet and that causes significantly more wounding of the target than if the bullet went straight through it.
Keyholing, or tumbling, can also be caused by using a bullet that is not compatible with a given rifling twist.
That is correct.....Most bullets tumble on impact in the M16....it is the boat tail style bullet that tumbles the best......I figured it would raise a long conversation about it I just dont have the time to go into detail............If anyone has any doubts just go online as there are boat loads of info about this topic.....
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rayzer007
Guest
The knowledge and professionalism on this forum never cease to astound me; and I do not say that lightly. What a treasured place! Absolute quality, unmatched anywhere else on the internet. It is such a privilege to be a member here.
Ray
Ray
I'm sure that all of us learn something here, Ray. It's almost every day that I pick up something new.
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mukwah
Guest
I also saw on a show about M16's, sorry I can't remember which one, that after a certain long distance the bullet can become unstable in flight and cause the keyhole situation. The person said that it could happen to any bullet once it slows to the point it no longer "flies" properly.
It's called keyholeing 'cause it just makes a funny looking hole in a target and you usually wouldn't know it's happening 'till you see the hole. Very inaccurate. The exception is if it's so severe it makes a twwwwwwang like a richocet. THOSE babies fly off to who knows where?
My take on .223s is they're like a Porsche 911, more stable going backward, but still, pretty stable. Light in the front, weighted in the rear and powered from the rear, it's not unusual for them to swap ends and do a 180 when de-stabilized for any variety of circumstances.
My take on .223s is they're like a Porsche 911, more stable going backward, but still, pretty stable. Light in the front, weighted in the rear and powered from the rear, it's not unusual for them to swap ends and do a 180 when de-stabilized for any variety of circumstances.
I wonder what that "certain long distance" is. It's my understanding that competitive shooting takes place out to 600 yards with the 5.56 cartridge. That would not be practical if the bullets became unstable in the air. Most sources I've seen claim that the maximum effective range for a "point target" (as opposed to an "area target") is 550 meters (601.5 yards).bigdogdaddy said:
From my readings...most of the tumbling takes place after the bullet impact. Like stated in previous posts...pretty hard to have true bullet flight any other way. A tumbler would pretty much be UNSTABLE in tragectory. Interesting subject.
The longer the bullet the more twist it needs to stabilze the bullet.
When the bullet is not stabilized they call it yaw. When the bullet is rotating the back of the bullet is a little off center so when the bullet hits it always goes sideways.
When you choose the rate of rifling for the .223 you decide where you want to stabilize or key hole. The longer the bullet you use the faster the twist you need to stabilize it.
I'm not good with words but I hope this clears up things a little. LOL
RICHGCOOP
DROID3 - Tap talk
When the bullet is not stabilized they call it yaw. When the bullet is rotating the back of the bullet is a little off center so when the bullet hits it always goes sideways.
When you choose the rate of rifling for the .223 you decide where you want to stabilize or key hole. The longer the bullet you use the faster the twist you need to stabilize it.
I'm not good with words but I hope this clears up things a little. LOL
RICHGCOOP
DROID3 - Tap talk
...have to remember to check the muzzle brake and crown. Any irregularities in those areas nicking the bullet upon exit will pile on a heap of keyhole probs. Also, The barrel should be inspected for fouling as well...grooves loaded with debris will effect functional twisting to some degree. JMHO
Tarheel
Tarheel
That makes perfect sense Rich. I would also think that how "hot" the round is would make a difference too. I would think (I don't know) that a big slow round like my .45 could also become unstable at longer distances.
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rayzer007
Guest
As far as a bullet tumbling goes - On a revolver if the cylinder does not index properly, it will shave some of the bullet off one side and make it tumble. If you buy swedged bullets they are too soft to take any speed and will strip the riflings and cause them to tumble.
RICHGCOOP
DROID3 - Tap talk
RICHGCOOP
DROID3 - Tap talk