Funny story, and related to this topic (I SWEAR!).
The scene: Towards the end of 1995, my unit 3ID 3/4 Cavalry is selected to participate in Operation Joint Endeavor as part of the new IFOR peacekeeping forces (weren't renamed SFOR until later). I am the driver of C41, platoon leader's tank, 4th platoon, C troop.
The Squadron is deployed in a massive, whirlwind training exercise to first Hohenfels (maneuver training area) and then Grafenhohr (gunnery training area) for some final training before deployment. Needless to say, by the time we hit the tank range at Graf, we were exhausted.
The first stage of a tank gunnery run has the tanks pulling forward and backwards in fighting positions in which you can have the tank completely below the level of the ground, with only the sights exposed: "Turret down", and allow you to fire once you pull up (on to a higher plateau) and expose the turret: "hull down". Basically it is a BIG foxhole. On the normal Graf ranges, the fighting positions are made of concrete and really well mapped out and cleared, but since we were training to deploy, we were set up on a range that had NOT been pre-prepared, for realism. The engineer batallion dug us the fighting positions earlier in the day.
We proceed through the day fire without incident (except for enjoying the pretty sparkles that .50 BMG API rounds produce on impact), and begin the night-fire. Shortly before they were scheduled to go downrange, the platoon sergeant's tank C44 breaks (I don't remember how exactly). My tank finished up early, and the Lt. volunteers our tank to the crew so they can qualify. Not trusting anyone else with "my" tank, I volunteer to drive with the crew (instead of sleeping). Now, as a driver, you have to know how far to pull up and back, or you will expose more of the tank than would be safe in battlefield conditions. During the DAY this is obvious, as you can SEE, but during the night, it is SOP to use chem-lights staked on the back-side of the berm, and watch those through the crappy low-light scope we replace the center vision block with. We went down to the fighting position built for the Platoon Sgt's tank WAAAY over on the right side of the range, and got ready. We fire 2 engagements without incident, but when I pulled up for the third, my left side chem light vanishes. I think about this for a second and scream "WAIT!!" through the intercom, but the gunner fires anyway. There is a "WHAAANNG" sound, followed by the loader cursing loudly. Cease fire is called, I pull the tank back and we get out.
The engineers had dug too deep to the left, giving an almost imperceptible cant to the tank, and when the gunner slewed the gun tube to engage the targets WAAAY over to the right, I was pulling up, and he buried the end of the 120mm gun tube into the 5 foot thick berm. And fired. The gunner could not SEE the berm, because of height over bore difference, and since I was tired, I did not remember what was behind that chem-light until it was too late. The loader had just sprained his wrist as a part on the breech had flown off and hit him.
The end of the gun tube was all bent back like a banana peel on the bottom. A foot long section of the tube had bounced off the hull six inches in front of my driver's hatch and flown back over to land behind the tank. I still have it. [:)]
All this because the M1A1 has a 3 foot height over bore difference [:D]