Military History/Steel Ball
We live in Antelope CA, close to the Roseville Rail yard that had an explosion in the early 70's. While digging in our back yard to run some pipe I came across a steel ball, no markings I can find, appears to be 3 1/2" in diameter and weighs about 5.5 pounds. Is there any type of munitions from the late 60's or early 70's that this can be part of. From what I understand the explosion in the Roseville rail yard was a bunch of Vietnam era munitions. Or could this be some type of old cannon ball?
First off, solid shot were made of iron, not steel, and came in very uniform diameters dictated by weight of the projectile.
Cannons were labeled by weight rather than calibers in modern guns.
The predominate weights were 2, 4, 6, 12, 18 and 24. Here is a chart:
As you can see the diameters were somewhat odd, since the bore had to account for windage, that is a slight gap between the shot diameter and the barrel bore.
In the event, none of the diamters or weights correspond to your measurements.
Now, if it had been a modern projectile, the closest it would have been a match to would be a cluster bomblet.
The LBU-30 submunition or bomblets ar the size of at tennis ball and are made of "pot" metal. If this is what you have it could still be hazardous and explosive.
Another thing you might have is a plane old steel ball from an industrial ball mill. These are similar in their use to the old rock polisher but much larger and are used to crush rock to different size grades. Material is placed in the mill and "tumbled" with these steel balls until the finished product reaches the correct size.
A lot of people are being sold these in place of real civil war iron cannon balls.
You might see if there was ever an industrial ball mill in operation in your area. Sacramento has changed so much over the years that there could have been one, or it was an escapee from a train. I would rule out an Iron cannon ball, but be wary of the CBU submunition.