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Discussion Starter #1
Today I went to the range and experienced the phenomena of "bullet tumble." I was wondering what causes this? While at the range I shot some relaods that were 185 gr wadcutters, they tumbled and made very distinct holes in my target. I then changed to PMC 230 gr FMJ and they didn't tumble. Does this mean that something is wrong with my reloads? ( of course I know the answer is yes, but what would yall recommend? )
 

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What load were you using? Most likely too light......

[This message has been edited by shane45-1911 (edited 07-18-2001).]
 

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The bullets could have also been very undersized for your barrel.

They could have been way too soft and leaded your barrel severely, resulting in a smoothbore until the jacketed rounds cleaned it out. This is the more doubtful theory.
 

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Bullet tumbling, or "keyholing" has been attributed to rifle bullets traveling at extremely high velocities. The early testing phases for what turned out to be the .223 round for the M16 used .177 bullets traveling at around 10,000 fps. They were traveling too fast to maintain stability in flight.

Were your wadcutter charges within loading table recommended limits?

Were the wadcutters damaged or distorted at any time before firing? A wadcutter presents what should be a symmetrically notched circular face to the air it travels through on the way to the target. If it is not circular, or the notches are not symmetric, air will not press evenly on the front end of the bullet during flight. IOW, the pressure wave the bullet forms as it flies through the air will not be a smooth cone. That could force the bullet to try to tumble while in flight. If it flies long enough, and the bullet distortion is big enough, it could hit the target sideways, thus forming a "keyhole."
 

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Just a couple points. I don't want to nit-pick, but 10,000 fps is not possible using gunpowder as a propellant. The max is around 6,500, and is constrained by the maximum rate of expansion of the gas generated by the burning powder. Also, stability of a projectile is related to velocity, but only as a function of spin rate. Unless the projectile is on the very edge of stability already, small changes in velocity are unlikely to make a difference. Best guess is undersized bullets not getting "spun up" properly, or a very light load not allowing the bullets to obturate into the rifling (same end result as undersized bullets).

Patrick
 

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Discussion Starter #6
Thank you VERY much for yalls replies. I have a MUCH better understanding of "keyholing" now and I believe I might have isolated the problem. Im still checking but I think the bullet casts were bad. Long story short, I think I might have just loaded over 1000 imperfect "keyholing" rounds. Next question, what in the world should I do with them???
 

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I dont know how far you were shooting when you had the keyholes but the shorter the range the less chance of a keyhole. This is not always true, but you might be able to use them at short yardage when you do some close quarter drills.

You could get an inertia bullet puller and pull them and salvage the brass, powder and primer. Its a little work and sort of noisey but its a thought.
 

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psween,

I haven't checked, but you're probably right. I didn't believe the 10,000 fps when I first read about it many years ago, but a little digging confirmed it. The velocity was reached during prototype testing to see if it was possible to manufacture a small caliber/extremely high velocity round for military use. As I recall, no one knew if it was even possible to reach such velocities, but they decided to try, and see what happened.

I doubt that any of the researchers felt that they could successfully develop a service round with such velocities, but they wanted to see what would happen, or even if it was possible. As a result, they used special propellants under special conditions that they knew would likely never be used for practical applications. Such is the nature of fundamental research.

What came out of the testing was the decision to develop a round to replace the 30 caliber round that was in use at the time, then call for the gun makers to design and build a gun for it. What ultimately came out of all this was the .223, and Stoner's idea to shoot it.

Ag2001,

Ken Neal is right. You can still use them for close quarter drills where keyholing is not so critical. It's not as time consuming as disassembling the cartridges and recasting the bullets.
 

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I'm a little late here but...did you check your target? What I mean is this. I thought for sure my bullets were tumbling too. I was shooting FACTORY 230gr RN when I first picked up my lastest 1911. Needless to say I was a little bugged considering I just dropped $600 on it. I showed my target the Head Range Master. He told to relax, it's not the gun or the ammo. Then he proved it. He re-set my target stand making REAL sure it was parallel with the firing line. Then he secured my target completly flat so that NO AIR could pass between it and the cardboard. Problem solved. As it turns out this is what was causing my "bullet tumble" problem, a slightly off angle target stand and a slightly loose target(some air was getting behind it). This combination cause my bullet to hit the target almost on it's side. Anyway, just a thought. Good luck. Hope your back shooting soon.
 

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Discussion Starter #10
Here is another update. First, let me answer lodraw's question. Yes, I tried two targets at 15 and 25 yards. Both keyholed. Second, I shot some PMC rounds and they did fine at the 15 yard target. The only thing that I have changed with the particular handload is the bullet. (The bullet maker was bought out by another company.) So as best I can tell it has to be a badly cast bullet to blame. BTW, the bullet measures .453 which is good. Im using a 185 gr. wadcutter, 4.7 gr Super target and Fed primers.

Second update: A person that shoots this same handload says that he shot 1500 of these bullets and none tumbled? Now what do yall think? What should I do? Im going to the range tommorow for further testing. I will let you guys know what I find out.
 

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Discussion Starter #11
Lodraw was right. I did a retest today and it seems that the paper targets weren't setup right. Thanks for everyones help. Maybe next time I will shoot cardboard targets.
 
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