November 30, 2012, 05:31 PM | #1 |
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keyhole in target
Whats the reason for the bullet making keyhole or oblong hole in target instead of nice round hole. A friend had this to happen while sighting in for hunting.
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November 30, 2012, 05:36 PM | #2 |
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Was the target fastened firmly to the backboard? Targets loose from the backboard are the cause of more keyholed bullet holes than bullets not being stabilized. Without any more info it's hard to make an informed guess.
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November 30, 2012, 05:37 PM | #3 | |
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Quote:
Longer answer: if the bullet isn't spinning at a high enough rpm to stabilize it, it will begin to lose it's axis and will eventually tumble. There can be many things that cause this. If we know more about the firearm being used, we can make a better analysis. |
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November 30, 2012, 05:41 PM | #4 |
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And include details about the ammunition that was being used.
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November 30, 2012, 05:44 PM | #5 |
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Thanks, I think it was factory ammo and the target was stable. I was thinking maybe real low powder charge.
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November 30, 2012, 06:02 PM | #6 |
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I had this happen once with 223 in a very light bullet (40 grn) in a medium fast twist barrel 1:9", at max velocity (over 3,500 fps), and a hot barrel, at a 50 yard target. I am pretty sure it was caused by one or more of the above.
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November 30, 2012, 09:56 PM | #7 |
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I have not read anything in this thread that would cause a bullet to tumble at short range. I think the bullet was flawed st the factory based on the info supplied.
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November 30, 2012, 10:57 PM | #8 |
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Sometimes the gun is the cause.
Is there damage to the crown? Is the bore in good condition? Is the ammunition correct for the gun? Not knowing all particulars, but anything between the gun and target? A bullet hits anything in flight can make it tumble. Even a 50BMG will tumble after hitting a quarter inch twig.
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November 30, 2012, 11:34 PM | #9 |
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Need to match the rifle twist to the weight of the bullet.
I've seen bullets tumble at 50yds bad enough to throw a 16" pattern instead of a single hole group with the right pairing. |
December 1, 2012, 10:43 AM | #10 | |
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Quote:
What ammo, manuf. bullet weight, gun manuf., we need specifics to give a good answer. Anything else is guess work.
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December 1, 2012, 06:09 PM | #11 |
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I had this happen with a 300 Savage back in the dark ages when I first started handloading. A friend was showing me how to reload and the velocity was too low to stabilize the bullet.
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December 1, 2012, 06:52 PM | #12 |
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Low velocity can easily fail to stabalize a heavy for caliber bullet. High velocity can easily overstabilize a very light for caliber bullet. A bullet that's less than bore diameter can strip off the rifling and get no stabalization at all. Pick your choice, all of them produce in-flight tumbling, .
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December 1, 2012, 06:56 PM | #13 |
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No caliber, no rifle info, nada Sheese.
I am gritting my teeth as I want to go max sarcastic and probably get a note from moderator, but come on. Before we respond make the OP give some info or don't replay. First guy up ask for info and then everyone cease fire until we get it, or not. ok, I am done. |
December 1, 2012, 09:43 PM | #14 |
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Generally its from the bullet not spinning fast enough to stabilize but without knowing what size bullet, what caliber, what weight bullet, what twist rate of the barrel, handload, factory load, ect. alls anyone can do to help you is guess.
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December 1, 2012, 10:45 PM | #15 |
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Heavy bullet with not enough twist.
Loaders:
I used to have a Rem model 7 in 223. It had a one in twelve twist rate. Shot nice groups with 40-55 grain bullets. I loaded up some 68 grain bullets and they all tumbled. Now I shot a savage in 223 with a one in nine twist rate. Haven't tried any light bullets, but with 55 grains and up . . .it's tack driver. I mean really. Live well, be safe. Prof Youing |
December 2, 2012, 12:37 AM | #16 |
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I got keyholes with undersized lead bullets out of my CZ. Took a 358 to stabilize.
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December 2, 2012, 01:14 AM | #17 |
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Here is an interesting twist, I used to have a Virginian Dragoon 44 mag with a 8 3/8" bbl. It would shoot jacketed bullets just fine, but 240 swc's at 800 to about 900 fps it would throw a couple keyholers with each six shots fired. The crown looked fine and the gun shot everything else great. Never figured out that problem with the velocity.
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December 2, 2012, 07:58 PM | #18 |
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Thanks everyone for the info, I realize i should have given more info to get some good answers. It was my friends rifle and factory ammo, I had read about keyhole hits before but didnt remember what it said. I just threw that out there to get ideas.
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December 3, 2012, 12:18 AM | #19 |
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I have had 75 gr Vmax keyhole from a 1 in 14" twist 6mmBR.... twist rate too slow.
I have had a .310" bullet keyhole in a .314" groove 303 Brit ..... bullet not getting traction on twist. I have had oblong holes in the target where the wind picked up part of the target and bent it..... bullet hits target at an angle.
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December 3, 2012, 08:55 AM | #20 |
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For factory ammo to keyhole, it's usually a problem with the rifle and not the ammo.
First thing to check is that the ammo is the same caliber that's marked on the barrel. For instance a 30-30 round fired in a .32 special rifle. The next thing to check is the condition of the bore, especially at the muzzle. Is it clean and free of corrosion, pitting? Is the muzzle damaged, dented, where the bullet emerges? If so, the escaping gases behind the bullet could be causing it to tip as it leaves the muzzle. If the barrel bore is clean and in reasonably good condition, might there be a dent inside the bore where a front sight ramp screw hold might have been drilled a bit too deeply at the factory and the barrel steel is pressed into it? (Sounds weird, but exactly what happened to my friend's .35 Rem, Marlin 336.) If none of the above seems to be the problem, we'll need more specific information about the rifle and the ammo used. |
December 3, 2012, 11:48 AM | #21 |
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"No caliber, no rifle info, nada Sheese."
There's nothing caliber or rifle specific to tumbling bullets. |
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