what's this pointy thing? WWII-era butt plug?

August 20, 2013 1:45 PM

here's a photo. it appears to be aluminum and it's weighty for its size. It was among the possessions of an elderly, career US Navy retiree. Any ideas? Phone's for scale-- I know what that is.
posted by Mayor Curley to Home & Garden (17 answers total)

It looks like a shell casing.
posted by effigy at 1:46 PM on August 20, 2013

Are you sure it isn't explosive? Is there anything written on it? Looks a lot like one of these things.
posted by oceanjesse at 1:50 PM on August 20, 2013

Best answer: For example, here is a naval shell casing (this one is larger - 16 inch):

http://www.cyber-heritage.co.uk/cutaway/shell2.jpg

But you'll see a similar construction and screw base.
posted by effigy at 1:50 PM on August 20, 2013

Looks similar to some 25mm ammunition
posted by ghharr at 1:56 PM on August 20, 2013

It's a Plumb Bob.
posted by Confess, Fletch at 1:59 PM on August 20, 2013 [5 favorites]

I'd also wager it's a plumb bob.
posted by resurrexit at 2:03 PM on August 20, 2013

Looking at the page oceanjesse linked, it doesn't look like a shell so much as it does an artillery fuze.
posted by ckape at 2:15 PM on August 20, 2013

If it's a plumb bob, there ought to be somewhere to attach a string (e.g. a hole or something) at the other end.
posted by pipeski at 2:24 PM on August 20, 2013 [1 favorite]

Does it have a hole through the non-pointy end? If not then I'm not sure if it would be a plumb bob since the string needs to come through the center of the piece or else go all the way through and be tied above.
posted by dawkins_7 at 2:25 PM on August 20, 2013

57mm Bofors ammo?
posted by Sintram at 2:27 PM on August 20, 2013

It's a shell casing. Lots of soldiers kept them; some folks even engraved them in their spare time.
posted by infinitywaltz at 2:57 PM on August 20, 2013

Best answer: Does appear to be blue anodized aluminum. Looks way more like a shell than a plumb bob, to me.
posted by Rash at 3:34 PM on August 20, 2013 [1 favorite]

Best answer: Blue is the color of practice ammunition.
posted by Comrade_robot at 3:46 PM on August 20, 2013 [5 favorites]

Yep, I think it is practice ammunition. Could maybe be a bullet fishing weight, too.
posted by misha at 4:00 PM on August 20, 2013

Best answer: It's an inert 20mm cannon projectile. You know it's inert because of the blue color.

It is not a "casing". The casing is the brass shell that contains the powder, with the projectile sealing the mouth.

A cannon projectile differs from a bullet in that it's explosive. A bullet is simply simply a solid piece of metal.

The 20mm cannon is most commonly used as an air-to-air weapon, although they are mounted on Navy ships as anti-aircraft installments.

The most common 20mm gun is the Vulcan.

The projectile you have is the one loaded into the second cartridge from the left, seen here.
posted by dinger at 4:17 PM on August 20, 2013 [6 favorites]

dinger is correct; I meant "shell," not "shell casing."
posted by infinitywaltz at 4:27 PM on August 20, 2013

Navy veteran chiming in here to say that comrade robot and dinger are correct.
posted by seasparrow at 4:34 PM on August 20, 2013