Wild Bullet Oscillations Possible?

[envelope]

Has anyone ever seen a bullet's flight path oscillate wildly, depending on what yardage mark it's flying past? I'm not talking about bullet arc, drop, shooter error (okay, well sometimes ), or powder inconsistencies.

The other night, I was shooting Freedom 115gr FMJ, 124gr FMJ, 124gr XTP, 147gr FMJ in 9mm, and 180/165gr FMJ .40 cal through a G19 and both 9mm and 40 versions of the Shield. Since these were technically TMJ and the flood lights were on, you could see them fly quite clearly. At the <20yd mark, they would fly straight, but anywhere between the 20yd-70yd mark they would spiral out in a clockwise position a good 12-18 inches. Hitting the berm at 100yds, point of impact would be more or less point of aim, with the exception of a few with wider and longer oscillations.

My friend first noticed it and until I saw it for myself, I thought he was seriously tripping balls. All types of rounds that night through all platforms did this, with the exception of the 124gr XTP, which comparatively were like laser beams.

We theorize this could be from bullet deformations/non-uniformity because the XTPs flew straight. Additionally, it wouldn't be a powder charge inconsistency because that would cause inconsistent bullet drop, NOT oscillations.

Is this unheard of, or can someone explain this phenomena?





...comments around not buying cheap ammo will be unappreciated

[stilly]

Has anyone ever seen a bullet's flight path oscillate wildly, depending on what yardage mark it's flying past? I'm not talking about bullet arc, drop, shooter error (okay, well sometimes ), or powder inconsistencies.

The other night, I was shooting Freedom 115gr FMJ, 124gr FMJ, 124gr XTP, 147gr FMJ in 9mm, and 180/165gr FMJ .40 cal through a G19 and both 9mm and 40 versions of the Shield. Since these were technically TMJ and the flood lights were on, you could see them fly quite clearly. At the <20yd mark, they would fly straight, but anywhere between the 20yd-70yd mark they would spiral out in a clockwise position a good 12-18 inches. Hitting the berm at 100yds, point of impact would be more or less point of impact, with the exception of a few with wider and longer oscillations.

My friend first noticed it and until I saw it for myself, I thought he was seriously tripping balls. All types of rounds that night through all platforms did this, with the exception of the 124gr XTP, which comparatively were like laser beams.

We theorize this could be from bullet deformations/non-uniformity because the XTPs flew straight. Additionally, it wouldn't be a powder charge inconsistency because that would cause inconsistent bullet drop, NOT oscillations.

Is this unheard of, or can someone explain this phenomena?





...comments around not buying cheap ammo will be unappreciated

Nobody should really bag on freedom munitions cheap ammo since we have all pretty much partook in their black and usa koolaid...

With that said, can you shoot some more and make a movie? THAT would be really cool to see. They might have used some of the powder that was leftover from the movie Wanted if it was curving and all. OR maybe their duplexed loads somehow got mixed up with your batch... Any movies would be sweet though, I wanna see this. Hold on to that stuff.

Orrrrrrr, maybe you got warn barrels? undersized ammo?

[NytWolf]

Results of the barrel rifling and stabilization afterwards?

I would like to see if the "spiraling wildly" would decrease with a longer barrel.

[LynnJr]

What you are seeing is perfectly normal and is exactly how a bullet flies.

If you shoot 50 bmg tracers at 2300 yards the bullet takes off wide left and goes way high corkscrewing the entire time.Once it reaches peak height it drops what looks like straight down onto the target but it in fact is still cork screwing.

This is for bullets fired in the northern hemisphere.

[Carcassonne]

There are 3 spins the bullet makes: Yaw, Pitch and Roll.

If the light is just right you can see a smaller helix inside a larger helix: There is a tighter faster helix inside a looser slower helix.





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[Fjold]

Google "Gyroscopic precession"

[ironhorse1]

I've been thinking about this all say. The thing that sticks in my head is the fact the the field is lighted.

Could this be nothing more than a
strobe effect as the bullet passes between the lights?

Each light would refract off the bullet at slightly different angles.

This might produce the effect that the bullet is changing position in flight when in fact it is the angle of the lighting giving an illusion of position change.

I'm just throwing this out there as the lights are making the bullets visible.

Any bullets I've seen in flight rise and fall in a predictable trajectory.

If bullets were wildly occillating in fight no one could ever hit any target.

These are my thoughts. This would be a good one for Myth Busters to test.

irh

[ironhorse1]

" At the <20yd mark, they would fly straight, but anywhere between the 20yd-70yd mark they would spiral out in a clockwise position a good 12-18 inches. Hitting the berm at 100yds, point of impact would be more or less point of aim, with the exception of a few with wider and longer oscillations."

If this were really happening then a target at 50 yards would have an impact 12"-18" off of center. Then the bullet corrects its path and comes back to point of aim at 100 yards.

Since I don't see this happening when firing rifles or handguns I'm going with my previous post about the flood lighting giving the perception of erratic flight.

irh

[stilly]

OMG! First the HORNADY lies and now THIS! NO! BULLETS FLY STRAIGHT! DELETE THIS THREAD! I DUN WANNA SEE NO MORE OF THIS BLASPHEMY!

[ironhorse1]

From what I've seen, at the range, bullets seem to fly all over the place.

Hitting the benches, ceiling ,floor and occasionally the target.

But you have to watch out for those wildly oscillating bullets which can just about hit anywhere.

Just as eye witnesses are not really reliable. What you think you see may not be what is actually happening.

If it were not for posts such as this one, I could not possibly have more fun.

Maybe if they were shooting smooth bore muskets I would find the results more plausiable.

Otherwise it is just an illusion, a trick played by light and motion.

irh

[rm1911]

It could be related to super/sub sonic transition. Speed of sound is just under 1100 fps. Given a muzzle velocity of 1150-1200fps then right about when you started seeing funny things is when it would transition.

I've shot my 45 on a lighted 100yd range and you can see the bullet clearly from 50-60 yds all te way to the berm. Rather cool actually. Anyways, point is it's arcing but it's straight and I reckon it's because it leaves subsonic. I've also shot 22's and can pick them up well in the scope. Not so much with the eye alone. But they stay pretty much super all the way. At least the remmy GB's and federal bulk.

Of course lighting could also play a role. Remember that handgun bullets have poor BC's and they are not designed for long distance flight. Long being pretty much past 25-35 yds. And it makes sense because the effective range of a handgun round isn't much beyond that. So terminal performance is more important than long range accuracy.

[Whiterabbit]

I'm ging to go with not possible. The idea that precession or gyroscopic motion is the root cause may have credence until we see that the OP is suggesting an oscillation of 18 inches within 50 yards.

Not possible.

There's something else going on.

[johnthomas]

Maybe my eyes are old and slow, but I have never been able to see a bullet in flight.

[LynnJr]

The bullet is from a 9mm handgun and not a rifle.The bullet never flies straight to the target.
The picture by Carcassone is spot on but the human eye can't see those small increments.
If your doing a google search look for "coriolis affect" as well.

[Whiterabbit]

the coriolis effect is NOT at play here with the distances so small. You guys are looking at very very small effects and applying them to an 18 inch differential at FIFTY yards. There's something else going on.

The simple fact is that within 100 yards a bullet cannot deviate from a path by 18 inches and then turn around and go back. The deviation is just too great. We're looking at something else here.