One of my recent GeoSnippits tutorial videos called "GeoSnippits Geocache Navigator Tutorial Part Two" had an unusual geocache of which I found. It was a large tube that was two feet long, three inches in diameter with a large cap on the top and a nice handle on the sides. After the video aired on You Tube I received several posts and emails asking what this strange tube was. Quite frankly I didn't know.At first I looked over the internet, called several Army Surplus stores and still couldn't find an accurate photograph or name of the plastic object. Then today I stopped by my local Army Surplus store and there it was. The very item I was searching for. I again asked the store attendent what it was and they did not know but they said they had a few more in the corner and one had a label on it.
It said that it was a Cartridge for an 81MM Mortar M889. There was a bunch of category stuff most likely warehouse information but there it was. A transport cartridge for a mortar.
I purchased one for $7.00 and will most likely use it for a unique cache. Below are some shots to show you the inside and with the cap off. 
