Bullet or bb hole in glass?

[Boomerang]

My wife was asking about a hole she saw in the window of her hotel room in Atlanta.
She described it as a small hole with a larger hole on the other side.

She was describing it as a bullet hole.

My thought was it's a bb hole, but I think I remember hearing somewhere that those certain holes in glass are not bb or bullet holes, but breaks that happen from manufacturing defects.

The ones I've seen have a very small hole on one side and a very smooth, larger circular break on the other side.

Are these things bb holes in glass, or am I correct in my assumption that they are manufacturing defects that happen because of some other cause?

 

[ThomasT]

I am an insurance adjuster and get to look at lots of damaged glass in windows. I have seen glass that was shot, broke by hail, broke by wind and flying debris. Glass broke from stressed windows because of settlement of the dwelling but so far no factory defective glass.

 

[Jim Watson]

In my youth, a teeny hole coned out large on plate glass was surely from a BB gun.
If you could get in and recover the "jewel" then you were hot stuff.

 

[hdwhit]

Where in Atlanta was your wife staying? I ask because knowing the neighborhood can go a long way towards answering the question of whether this was a defect, a stress crack or a projectile.

Can she take a picture that you can post?

 

[Boomerang]

She didn't say where she was. We were having a conversation about airport vouchers and hotels, so maybe it was near the Atlanta airport?

 

[jmr40]

I've seen damage like that before. A bullet will pass right through glass. A BB, or even a rock picked up by a lawnmower will often hit the glass with enough force that it creates a cone like hole with the bigger diameter on the inside of the glass. The object that hit the glass doesn't penetrate, but will sometimes leave a tiny hole on the outside, sometimes not. It could have been a BB, or just as likely a small rock thrown by a lawn mower. A bullet would most likely have gone all the way through and left a hole at least as large as the bullet diameter. This is with the thick glass used in commercial settings, not the thinner glass windows used in homes.

 

[lemaymiami]

Your question about possible bullet hole in glass at a hotel brings back some memories... Many, many years ago while stationed in the Washington D.C. area (just before shipping out to a bad place on the other side of the world) I had a job working for an old family hotel on the edge of the redlight district (14th and K) in the evenings. Since my job was to keep the hookers out of the hotel it was an education in many different directions for a naive young man in 1970...

The first thing I was taught was.... it didn't happen here. If we were still mopping up the blood at the front door - our standard reply if reporters or anyone else asked about some kind of mis-adventure.... "It didn't happen here". Amazing the kind of things that didn't happen at that aging old "family" hotel... Your question really took me back to my roots in street life where my start in the dark side of the street began....

 

[buck460XVR]

Damage of some kind, not defect.

 

[CapnMac]

Most conical holes in glass are FOD (flying object or debris).

Glass is a relatively homogeneous material, the molten glass is pressed out between rollers and floated over molten tin (hence the term "float" glass). This creaes a certain anount of surface tempering, which couples thorugh the glass material to make the cone.

I have, however, seen "factory defect" glass. But, it was a very specialized instance involving tempered glass sheets set into curtainwall frames undergoing differential heating. (Was ugly, edge of glass would 'defeat' the main body of the glass along the weakness vector of the temper, which would pop the 80% center out of the outer pane several stories above ground.)

Bullets make round holes (with broken edges in plain glass, and crisp edges in tempered). That is unless they are spent, or ricochets that are near-spent.

 

[MarkDido]

Your question about possible bullet hole in glass at a hotel brings back some memories... Many, many years ago while stationed in the Washington D.C. area (just before shipping out to a bad place on the other side of the world) I had a job working for an old family hotel on the edge of the redlight district (14th and K) in the evenings. Since my job was to keep the hookers out of the hotel it was an education in many different directions for a naive young man in 1970...

The first thing I was taught was.... it didn't happen here. If we were still mopping up the blood at the front door - our standard reply if reporters or anyone else asked about some kind of mis-adventure.... "It didn't happen here". Amazing the kind of things that didn't happen at that aging old "family" hotel... Your question really took me back to my roots in street life where my start in the dark side of the street began....

I used to go to DC from Norfolk about 3 times a year when I was stationed there. I always stayed at the Crystal Gateway Marriott. I couldn't get a reservation there on one trip, so I stated at a hotel in DC proper. I want to say 24th and New York. You could still see the faint chalk outline on the carpet.

Bad choice!.

 

[buck460XVR]

If the wife was on the ground floor, the hole could have been made by a rock/stone from groundskeeping and their mowers/weedeaters, etc. Pretty common occurrence where they use colored rock/stone for landscaping.

 

[MartinS]

The cone is a spall, the thing that does a lot of damage when a tank, say, is hit by solid shot that does not punch a hole.