Page 1 of 2

Ricochets

Posted: Fri Apr 27, 2007 11:06 am
by TxD
This is an "Old School" FBI training film, however I learned something
interesting.
About half way through, there is a demonstration on ricochets off a
wall.

http://www.thesmokinggun.com/tsgtv/inde ... =TSGTVshlk

Posted: Fri Apr 27, 2007 12:06 pm
by kauboy
Wow, the ricochet portion was interesting. And the idea that you can predict, with at least some certainty, what a ricochet can do, is very surprising.

Thanks for the vid!

Posted: Fri Apr 27, 2007 3:12 pm
by kw5kw
kauboy wrote:Wow, the ricochet portion was interesting. And the idea that you can predict, with at least some certainty, what a ricochet can do, is very surprising.
Good pool players use the bank shot... think of the bank shot as a ricochet.

Russ
kw5kw

Posted: Fri Apr 27, 2007 3:28 pm
by stevie_d_64
I liked the video...

But the police officer in a suit and tie! Now thats classy! We need to see more of that out there! ;-)

Posted: Fri Apr 27, 2007 3:32 pm
by TxD
[quote="kw5kw"][quote="kauboy"]Wow, the ricochet portion was interesting. And the idea that you can predict, with at least some certainty, what a ricochet can do, is very surprising. [/quote]

Good pool players use the bank shot... think of the bank shot as a ricochet.

Russ
kw5kw[/quote]
---------------------------------------------------------------------------

Noted.

But that .38 is hitting the wall at about 30 degrees and coming off at
about 5 degrees to break the balloon 5 feet away.
Must have a little "english" on it. :razz:

Posted: Fri Apr 27, 2007 3:35 pm
by kauboy
No, actually he's right. When the ball to fall is against the rail, you have to "ricochet" the cue off the same rail, and it travels almost parallel.

I never thought about it, but yeah, thats a perfect analogy man.

Posted: Fri Apr 27, 2007 3:37 pm
by SC1903A3
You beat me to the draw. I just found this and was going to post the video. I also like the felony vehicle stop video. I love the smoking gun.

Posted: Fri Apr 27, 2007 4:19 pm
by jimlongley
Although they made a big deal in the film about the ricochet "traveling almost parallel to the object it ricocheted off of, they also pretty much disproved their own thesis.

Fired from about 40 feet away, the slug hit the ground and passed under the car rising to a point about 4 to 6 inches above the ground after traveling about 8 feet. I would bet that the slug was still going up when it went through the target, bullets and pool balls do not get to violate Newton's Laws of Motion.

If you hit a cue ball dead center, not too hard, with absolutely no english, and it hits a rail, its exit angle will be pretty close to equal to its incident angle, the only way you can get it to travel differently is by applying english or hitting it real hard so the rail distorts, something I studied a great deal in my misspent youth (pool ball english that is, I flunked the other.) :lol:

The wall shots against the balloons were probably splatter or smear from lead bullets, which might apply somewhat to the shotgun slug too, I have cut playing cards in half using that trick.

The reason the slugs' (pistol or shotgun) exit angles did not equal the incident angle is due to the absorption of some of the projectile's energy by the object that it hit, the road or wall, so it will depart at a lower angle, but still rising.

The same thing pretty much applies to shooting across the road at the man target or the balloons, the shotgun slug was a couple of inches above the ground when it reached the target, once again going up after contact with the ground.

The best way to demonstrate this is to skip a stone across some water. The distance from the first bounce to the second bounce will be less than from the thrower to the first bounce, and each succeeding bounce will be closer still. Obviously the projectile (and I have seen 5 inch projectiles skip merrily across the water too, as well as small arms fire, which is why I recommend skipping stones) loses some energy at each bounce, so its angle of departure and distance of travel will be reduced.

The "Dam Busters" in England used the same principle for bombing dams in Germany during WWII, all they needed to do was time the bounces to get the bomb, which was skipping across the water, to hit the dam at the same time as it was hitting the water after a couple of bounces. They had limited success.

This could make a great Mythbusters show with high speed cameras, like the .50 cal slugs breaking up on contact with the water.

Posted: Fri Apr 27, 2007 9:03 pm
by austin
A bullet is not round. It is long and it spins.

When it hits something, the resulting linear momentum change causes the bullet's center of rotation to change which is resisted by the bullet's angular momentum which is resisted by the object the bullet has come in contact with which pushes back on the bullet.

This does all sorts of things, one of which is the angle of incidence does not match the angle of reflection.

Posted: Fri Apr 27, 2007 9:11 pm
by austin
Skip bombing was used to devastating effect in the Pacific during WWII. This was also used on the French Fleet at Casablanca.

B25s and B17s ( or F4F ) at mast level would strafe a ship then the last bomber would drop his delayed fuse bombs.

The first pass by a B25 with 12 x .50 cal firing at the ship would kill all the AA crews and the bridge. The ship could then be bombed.

Check out this link. The pictures are from the rear of the lead bombers as the bombs hit.

http://www.grafixnpix.com/wwii/5thaafp2.htm

Posted: Fri Apr 27, 2007 9:18 pm
by lrb111
austin wrote:A bullet is not round. It is long and it spins.

When it hits something, the resulting linear momentum change causes the bullet's center of rotation to change which is resisted by the bullet's angular momentum which is resisted by the object the bullet has come in contact with which pushes back on the bullet.

This does all sorts of things, one of which is the angle of incidence does not match the angle of reflection.
Lead flattens, absorbing the impact and diminishing the reflect angle. Tt does not rebound as rubber might. But rubber bullets rebound!!

Posted: Fri Apr 27, 2007 9:24 pm
by stevie_d_64
There's got to be a geometric principle I am forgetting here...

Wouldn't there be some sort of credibility behind a traveling object regardless of speed and mass (maybe this is more of a physics issue)...

That an object traveling and striking a "surface", that the angle of "entry" or approach would generate an "exit" or deflection angle equal to that approach angle???

Thus it is almost elementary that it could be calculated from only imputing the approaching angle, the degree of the surface (the constant) in relation to the approaching object, therefore giving you a good idea of where that object could be deflected to with reasonable accuracy...

If anything I believe any of us who have shot pool, or firearms, can deduce without a "CRAY" computer where a round may ricochet off to???

I know there are lots of other factors and variable that could be plugged into this, but I just seem to recall a basic geometric equation or principle that you could apply to this issue...

I dunno, I'm done with homework tonight...

Laters...

Posted: Sat Apr 28, 2007 12:53 am
by KBCraig
I'd long ago heard the "parallel ricochet" tale, but I never saw it documented before. This is far from definitive, but it does show how the tale got started.

What I found interesting was the pistolcraft of the day. The "crouch/point" method was intriguing. All techniques shown were one-handed.

And then I wandered off into the other videos on that sight, and let me assure you that their "NSFW" section is not safe for work, unless you work in a VD clinic. Or unless you own the place, and can use them to horrify your 30-something business partner while chasing your 17 year old daughter out of the room with her hands over her ears.

:grin:

Kevin

Posted: Sat Apr 28, 2007 11:40 am
by txinvestigator
Wayyy back, an FBI SWAT leader used to make richochet demonstrations routinely for the Dallas Sheriffs Academy. I saw a couple of those.

The posted video is a good one. Interesting find.

Posted: Sat Apr 28, 2007 3:10 pm
by Glockamolie
I was taught the same thing in my police academy in 1994. Never have really tested it, though.