Why was this bullet visible?

[grauhanen]

On Friday morning I shot at 100 yards. It was calm and cool, about 5 - 6 degrees Celsius. As I've been doing, I chronographed the ammo.

On this occasion, and for the first time, I had a video camera on the targets. Except for a few brief clips of cats at home, or wind flags at the range, I've never made a video of shooting of targets. Nor until yesterday have I ever tried to edit a video.

On the third target's bottom left bull the first five rounds went unsurprisingly. The sixth shot was a flyer that had a significantly higher POI. It's MV was 1035 fps. The previous five rounds had MVs of 1030, 1040, 1032, 1032, and 1030 fps.

Later, when looking at the video of the mornings results, I found that the flyer, the sixth shot, was the only one that, for a fraction of a second, could be seen for a brief moment.

Below is a clip of the sixth shot. I have no idea of the frames/second information, but I believe I slowed down the video clip to 0.1X. I then slowed that clip by 0.1X again.

Why was this round visible?

There's a "thing" that appears near the bottom left corner early in the clip. It continues through most of the video up toward the right corner. It passes near the bullet's POI around the same time. As it's uninterrupted by the bullet, it must be extraneous and uninvolved. Perhaps it's a cold insect somewhere between the camera and the target.

The weird screeching sound that may be heard must be the product of the sound of the shot altered by the slow motion.

 

[OkayShooter]

Glare maybe?

As for the shot, light just hit right or just hit the right frame. I often seen my shots spiral in when shooting 100 @ the range I shoot F class.

I caught a Prometheus pellet seperate the core from the shirt.

 

[propliner]

You happened to catch that bullet in sync with the frame rate. The other thing was definitely an insect.

 

[grauhanen]

Glare? The sky was overcast and lighting was even. In sync? Perhaps.

Is it at all significant that of the 100 rounds captured on video, only one of them can be seen?

That sixth shot is the only visible one and it's the one that's quite a bit outside the group. In fact it's the worst shot of the 100. Why that one?

It was when I looked at the video at 8.5X normal speed that I first saw that the sixth shot was visible. It was easy to see. I looked at it at normal speed, and it was still the only round that could be seen. Whether in slow motion, actual live speed, or speeded up to 8.5X normal speed, that one round and none of the others is visible. One out of one hundred. And that one is the most abnormal, out-of-bounds flyers, of the 100.

Perhaps there's a connection between the two.

For anyone wishing to see the complete 100 rounds, speeded up 8.5 times, below is the original 1 hour plus, reduced to 7 minutes and 37 seconds. If you see any other rounds in addition to the one referred to, please advise. (For some reason unknown to me, one of the groups on the second target doesn't have sound.)

 

[_Shorty]

I often watch bullets drop into the target through the scope. Depending on the time of day and the angle I'm standing at I'll be able to watch another shooter's bullets fly all the way to the target. No reason you wouldn't sometimes catch one on video. Just a matter of lighting angles and the timing versus the shutter. Years ago I caught a few on video. Here's one at an open-sights fun match:

And a miss at a silhouette match.

 

[mcaswell]

It's entirely luck of the draw as to whether you get a frame with the bullet. If your video is recording at 30fps (which is what most TV is shown at), your chances aren't great. The camera is taking 30 pictures every second, which isn't that many when it comes to capturing a bullet.

There are many consumer cameras that'll get up to 240fps if you mess with the settings. Those will have a much greater chance. If you really want to see the bullet, you'll have to shell out for a slow-motion camera.

 

[_Shorty]

Rolling shutters that pretty much everything uses now will complicate it further, too. I also have some slow-motion silhouette target hits up on YouTube, and took a look at it to see if I could see any bullets. Until they hit, not really. And that was at 1080p and 240 fps. The angle wasn't good for that, though. You've got to be fairly straight-on with the target, and some distance from it, in order for a bullet to be in frame for a reasonable amount of time.

 

[grauhanen]

It's entirely luck of the draw as to whether you get a frame with the bullet. If your video is recording at 30fps (which is what most TV is shown at), your chances aren't great. The camera is taking 30 pictures every second, which isn't that many when it comes to capturing a bullet.

There are many consumer cameras that'll get up to 240fps if you mess with the settings. Those will have a much greater chance. If you really want to see the bullet, you'll have to shell out for a slow-motion camera.

The question isn't about how to capture a bullet in flight. It's not relevant or important. The question is why was only that particular round visible?

Some 99 bullets weren't seen. That's okay. They were ones that generally went to their POIs without surprise. The only visible round did not.

 

[Scotty454]

The question isn't about how to capture a bullet in flight. It's not relevant or important. The question is why was only that particular round visible?

Some 99 bullets weren't seen. That's okay. They were ones that generally went to their POIs without surprise. The only visible round did not.

You're obviously looking for some kind of correlation between the reason the bullet deviated and the bullet being caught on camera. But there isn't one, complete coincidence.

 

[grauhanen]

Below is an image of the bull that had the flyer, the sixth shot with an MV of 1035 fps. All ten rounds are shown, with the POI and MV of five other rounds.

The image shows the flyer at 1035 fps striking considerably higher than all the other rounds in the group. It also shows the fastest round at 1047 fps striking below several others with slower MVs.

On the right is the same bull with scales on either side for estimating vertical difference between points of impact.

 

[grauhanen]

You're obviously looking for some kind of correlation between the reason the bullet deviated and the bullet being caught on camera. But there isn't one, complete coincidence.

Calling it a coincidence is an easy solution. Is it a coincidence that the only bullet out of 100 that was caught on camera is also the only flyer? Coincidence makes sense if it were any other bullet of the 100 recorded.

Could there be a factor in made it a flyer that also made it visible? Something made that one round an egregious flyer. Bullets don't become flyers without reason.

 

[Scotty454]

Calling it a coincidence is an easy solution. Is it a coincidence that the only bullet out of 100 that was caught on camera is also the only flyer? Coincidence makes sense if it were any other bullet of the 100 recorded.

Could there be a factor in made it a flyer that also made it visible? Something made that one round an egregious flyer. Bullets don't become flyers without reason.

Yes, it is. Correlation =/= causation. Everyone that responded here unanimously concluded the same thing.

You also obviously came here looking for validation, rather than opinions. Sorry you didn't get what you were looking for, lol. C'est la vie.

 

[just having some fun]

what type of bullets are you shooting ?

are they plated ?

is it a flyer because the plating/ jacket came off ? and then bullet was unstable

 

[emerson]

Very interesting. Looks like velocity is not the culprit. Projectile lack of uniformity seems to be the issue.

 

[LeftFootOfDoom]

i have it happen on occasion through my scope, just put it down to right time/right place. Never put much thought into it. Doesnt happen every round or even every mag, but it does happen.
This is with cz455, 100m/200y, eley sport and rws tgt rifle. Originally had leup vx111 6.5-20, now with sightron s3 6-24. Just catch a momentary glimpse of projectile at top? of arc i think

 

[FLHTCUI]

I too have watched bullets downrange either through the naked eye or through the scope on target.
9mm from the then legal Beretta Storm and several times with the CZ 22's will subsonic and hyper sonic ammo.
O/P thanks for posting the footage cause it is something not everyone gets to see while at the range.
Rob

 

[_Shorty]

Calling it a coincidence is an easy solution. Is it a coincidence that the only bullet out of 100 that was caught on camera is also the only flyer? Coincidence makes sense if it were any other bullet of the 100 recorded.

Could there be a factor in made it a flyer that also made it visible? Something made that one round an egregious flyer. Bullets don't become flyers without reason.

It's nothing but a coincidence that any bullet with that video shot setup would happen to catch the bullet/shutter relationship just right in order to be seen. The only meaningful variables involved there are the amount of distance travelled being caught by the camera, shot velocity, and video framerate. You just have to luck out that the bullet happens to be within that travel distance when the shutter is "open." Whether it is a flier or not isn't related. Here is what is likely the main reason you get fliers:

That's G1 BC data for 100 shots of Eley Tenex. (Eley says they should have a G1 BC of 0.140, so this test was pretty close.) The "valid tracks" value shows 95/100 shots were within 2x the standard deviation of the BCs of all shots. The remaining 5 were ignored for the average BC calculation, deemed to be outliers due to being beyond 2x the SD for BC. The signal quality was good, and none of the shots were ignored for poor signal to noise. All the ignored shots were ignored due to being abnormal/outliers. The first number after the filename is that shot's G1 BC, and after the comma is a number related to the signal to noise ratio.

Shot 1's BC was only 79% of the average value. I'd bet that hit low.

Shot 21's BC was only 87.9% of the average. Bet low again.

Shot 51's BC was 82.7% of the average. Bet low again.

Shot 57's BC was 110.9% of the average. I'd bet that one hit high.

Shot 73's BC was 86.6% of the average. Bet low again.

Whether or not they hit high or low would also depend on their velocities, and state of barrel tune. The further a shot deviates from the average BC the more the amount of velocity it sheds on the way to the target is going to vary from the average. Shot 57 is going to shed way less velocity than the average with that much higher than average BC. Shot 1 is going to shed way more than average. And those differences are going to play into how much drop each shot has, on top of all the other things that affect shot placement.

What causes any of the shots to be BC outliers with regard to that data? Probably just bullet shape abnormalities. Perhaps shots 1, 21, 51, and 73 had some kind of dings and dents in them. And perhaps 57 was absolutely pristine, or had some fluke dings and dents that just happened to improve aerodynamic properties rather than harm them. Hard to say, but what is clear is that for whatever reason they had aerodynamic qualities that differed substantially from the norm for that batch.

 

[grauhanen]

Yes, it is. Correlation =/= causation. Everyone that responded here unanimously concluded the same thing.

You also obviously came here looking for validation, rather than opinions. Sorry you didn't get what you were looking for, lol. C'est la vie.

Although the previous posters (four including you) opine that it's a coincidence that in itself doesn't mean that they must be correct. A guess isn't correct simply because it's repeated.

You dismiss the possibility of a connection between a bad flyer and it being visible yet don't offer a reason for rejecting it. Dismissing it simply as a coincidence seems at best premature. It's possible there's an explanation.

what type of bullets are you shooting ?

are they plated ?

is it a flyer because the plating/ jacket came off ? and then bullet was unstable

The ammo in question is .22LR match ammo. It isn't plated.

 

[_Shorty]

Although the previous posters (four including you) opine that it's a coincidence that in itself doesn't mean that they must be correct. A guess isn't correct simply because it's repeated.

You dismiss the possibility of a connection between a bad flyer and it being visible yet don't offer a reason for rejecting it. Dismissing it simply as a coincidence seems at best premature. It's possible there's an explanation.

Occam's razor. Besides, what possible gain is there if you have indeed discovered that bullets are invisible to cameras unless they're fliers? Just move on with life.

 

[grauhanen]

Very interesting. Looks like velocity is not the culprit. Projectile lack of uniformity seems to be the issue.

I agree. The errant round's MV was not the issue. In comparison with the nine others in the group (and 99 others of the 100), there was something about this round that caused it to have an irregular trajectory or flight that didn't occur with the other rounds. Regardless of what's seen or not seen in the video, this round had an unpredictable POI.

Of the 100 rounds shot, every other one went as might be expected. They had reasonably predictable trajectories. Something was different with the flyer.

What was different? A lack of uniformity seems like a possible and reasonable explanation. How might a .22LR bullet be lacking in uniformity? Bullet shape and symmetry may have been less than ideal.

The bullet heel is a potential culprit. If it is misshapen or malformed, it will result in the bullet's flight being unpredictable. Another potential problem is an inconsistent center of gravity. Soft lead projectiles like .22LR bullets and airgun pellets are very difficult to manufacture with a perfect center of gravity. Center of gravity variation is the cause of bullet dispersion rate variation. That's why some lots shoot better at distance than other lots. It also applies to rounds within lots.

Is there another cause for the unpredictable trajectory for this one errant round?

Is it possible that this one round's irregular trajectory -- caused by either a misshapen bullet heel or a very inconsistent center of gravity -- helped make the round briefly visible?

Finally, if the round has an center of gravity issue, would it cause the round to corkscrew?