squib load
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I was shooting my kentucky 45 using 45 grains of 3f the other day and I was getting keyholes.When I went to 50 grains it punched a nice round hole.Thanks,squib
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Can a round ball keyhole?
- Thread starter squib load
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paulvallandigham
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NO, a round ball doesn't " Key -Hole"! However, if your target paper is backed by a piece of cardboard or wood with prior holes in it, the paper can tear from one side of the ball hit , so that it appears to be elongated. this if often mistaken for Key-holing, even when bullets are fired. The first REAL keyhole I saw was fired from a .22 pistol, which had such a worn out barrel, that the bullet tipped, or " Yawed" to one side as it went through the target paper. It did this to a smaller or greater extent with every shot fired. The bottom end of the bullet left a flat side to the slot of the " key-hole", making that distinctive marking.
I was also present at my range when one of the guys thought he had a key-holed RB. when we inspected the target more thoroughly, it became evident that someone else had fired a ball in his target by mistake, and the two hit close enough together to produce the elongated hole in the paper. A man shooting next to him admitted it was probably his shot, as he had one less ball hole in his target than he shot.
When examining paper targets, remove them from their back support. Now, carefully, use your fingers behind the target to fold the edges of the hole back towards the front of the target. That way you get a much clearer picture of what actually caused the paper to tear. :hatsoff:
I was also present at my range when one of the guys thought he had a key-holed RB. when we inspected the target more thoroughly, it became evident that someone else had fired a ball in his target by mistake, and the two hit close enough together to produce the elongated hole in the paper. A man shooting next to him admitted it was probably his shot, as he had one less ball hole in his target than he shot.
When examining paper targets, remove them from their back support. Now, carefully, use your fingers behind the target to fold the edges of the hole back towards the front of the target. That way you get a much clearer picture of what actually caused the paper to tear. :hatsoff:
I've often wondered if a PRB was loaded w/ a very tight patch, would the RB itself become deformed...like an elongated RB w/ straight sides? If that was the case, then it would be possible for it to keyhole because it's no longer round......Fred
paulvallandigham said:
There is no more to say to keyholes by RB.
Real key holes are from Maxiball's for example. If that occurs, you use either not enough powder to compress the maxiball in the first place. But that is unusual.
It occurs when the tail is even only slightly dammaged. The tail must be perfect. A flatted nose, though bad is less worse than a damaged tail.
Billnpatti
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There is no way for a round ball to keyhole. Only a conical bullet can keyhole. What likely was happening was the backing for your target was not tightly up against your target and allowed the holes to be torn in your target leaving ragged oblong looking holes. I have had this happen to me when the backing on which I placed my target was warped or bowed away from me. I suspect that your second targt was placed on a different backing which was flat and the target was flat against it. This would cause the holes to be nice and round as you described.
This is my best guess for why you got what appeared to be keyholes when shooting patched round balls. The guess is free and worth every penny. :thumbsup:
This is my best guess for why you got what appeared to be keyholes when shooting patched round balls. The guess is free and worth every penny. :thumbsup:
squib load
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Thanks,all the answers seem to give the reason it key holed.My top target was loosely fitted over the target under it.squib
nchawkeye
58 Cal.
Once you pull the trigger that round ball ain't round anymore...It then becomes an oblate sphere...
zimmerstutzen
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There is another way for roundballs to key hole. However they have to be so off course that they pierce the target at an acute angle. for instance bouncing up off the ground or off a target upright. A roundball piercing the target at or near a 90 degree angle will not keyhole.
An elongated bullet must be spun above a certain RPM in order for it to maintain its "point forward" attitude while in flight.
The speed needed to "stabilize" it so that it maintains this attitude is totally dependent on its length and diameter. Actually it is the ratio of length to diameter that is important.
If the bullet is not spun at or above this rotational speed it will begin to tumble as it fly's thru the air and, if it hits the target while it is somewhat sideways it will produce the typical elongated "keyhole" that some of us have seen.
As I mentioned, the length and diameter are the determining factors in the necessary speed to stabilize the bullet but, simply put, for any given diameter, the longer the bullet is, the faster it must spin.
To picture this in a common way think of a top.
Short fat tops will remain stable at fairly low speeds but tall skinny ones must be spun faster or they will wobble to the point that they will not work as a top at all.
This is the same force we are discussing.
Since a roundballs length is extremely close to its length, even when obturation is taken into account, mathematically it does not have to spin at all to prevent "keyholing".
In other words, it doesn't need to spin to prevent this phenomena.
A roundball must be spun to prevent another thing from deflecting it from its line of flight.
After leaving the muzzle at a high rate of speed, the blast of wind against the front and sides of the ball produce a tremendous force.
As long as this force is equal in all directions the ball will continue on its straight path (although it does travel in a arc relative to the ground due to gravity).
The problem is that none of the roundballs we shoot are prefect and very slight variations of shape and roughness on the surface will alter the force of the wind resulting in a sideways deflection.
If the roundball is not spinning, these unequal forces will deflect the ball in some direction other than the one in which it was aimed.
If the roundball is spinning on an axis which is parallel with its line of flight these aerodynamic forces are still trying to deflect the ball however because it is spinning the direction of the unequal force is constantly changing around the line of flight so, in the end, the force will cancel out its own effect.
One could almost say that the unequal force was almost pushing in all directions around the line of flight at the same time as long as the ball keeps spinning.
This is why a roundball barrel can use such low rates of twist and still shoot accurately.
The bottom line in my book is that a roundball cannot "keyhole" unless it hits something to cause it to spin on a different axis.
Even if this happens it will not produce any visual evidence on the target that this is happening.
If the holes in the target are long and not round it is caused by the paper the target is made from or the backing that the target was taped or stapled to.
I have seen targets with these odd looking holes in them but it was always caused by the cardboard backing ripping as the ball passed thru it and slapping back at the paper target thereby ripping an odd looking hole.
This seems to only happen when low velocity shots are made. Faster velocities tend to poke the same round hole thru the cardboard that one would expect.
The speed needed to "stabilize" it so that it maintains this attitude is totally dependent on its length and diameter. Actually it is the ratio of length to diameter that is important.
If the bullet is not spun at or above this rotational speed it will begin to tumble as it fly's thru the air and, if it hits the target while it is somewhat sideways it will produce the typical elongated "keyhole" that some of us have seen.
As I mentioned, the length and diameter are the determining factors in the necessary speed to stabilize the bullet but, simply put, for any given diameter, the longer the bullet is, the faster it must spin.
To picture this in a common way think of a top.
Short fat tops will remain stable at fairly low speeds but tall skinny ones must be spun faster or they will wobble to the point that they will not work as a top at all.
This is the same force we are discussing.
Since a roundballs length is extremely close to its length, even when obturation is taken into account, mathematically it does not have to spin at all to prevent "keyholing".
In other words, it doesn't need to spin to prevent this phenomena.
A roundball must be spun to prevent another thing from deflecting it from its line of flight.
After leaving the muzzle at a high rate of speed, the blast of wind against the front and sides of the ball produce a tremendous force.
As long as this force is equal in all directions the ball will continue on its straight path (although it does travel in a arc relative to the ground due to gravity).
The problem is that none of the roundballs we shoot are prefect and very slight variations of shape and roughness on the surface will alter the force of the wind resulting in a sideways deflection.
If the roundball is not spinning, these unequal forces will deflect the ball in some direction other than the one in which it was aimed.
If the roundball is spinning on an axis which is parallel with its line of flight these aerodynamic forces are still trying to deflect the ball however because it is spinning the direction of the unequal force is constantly changing around the line of flight so, in the end, the force will cancel out its own effect.
One could almost say that the unequal force was almost pushing in all directions around the line of flight at the same time as long as the ball keeps spinning.
This is why a roundball barrel can use such low rates of twist and still shoot accurately.
The bottom line in my book is that a roundball cannot "keyhole" unless it hits something to cause it to spin on a different axis.
Even if this happens it will not produce any visual evidence on the target that this is happening.
If the holes in the target are long and not round it is caused by the paper the target is made from or the backing that the target was taped or stapled to.
I have seen targets with these odd looking holes in them but it was always caused by the cardboard backing ripping as the ball passed thru it and slapping back at the paper target thereby ripping an odd looking hole.
This seems to only happen when low velocity shots are made. Faster velocities tend to poke the same round hole thru the cardboard that one would expect.
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Let me shoot two roundballs from the bench, I'll show ya's a keyshole. :grin:
Sure they do it all the time when fired from smoothbores; you just can't see it on paper because they are round or nearly so. It has very little effect on accuracy when compared to a conical bullet that keyholes. Its accuracy is out the window in just a few yards.
squib load said:
My first question would be "how would anyone know it "keyholed" just by looking at the target? A ball is the same all the way around. Smoothbore holes in targets look just like the holes made by a rifle with the same ball.
The velocity change was likely the key in making cleaner holes.
Dan
hanshi
Cannon
Key hole? Naaah!
