A Very Rare Brunswick Iron-slag Cannon Ball Dated 1575

[fernando]

I am very pleased to have received one of these cannonballs. The date and monogram are well visible, much more in real than in pictures.
I wish Michael was here so that i could exchange with him a couple perspectives arising from this thread he started, as follows:
Assuming the person in the markings is indeed HEINRICH JULIUS (1564-1613), we would have that, at the date these cannon balls were cast, he was only eleven years old. Is this plausible ? I have tried to find any event on his life referring the date 1575 but, among many dates, this one doesn't appear.
I could also ask why the monogram is composed of three letters, as it could also be a pair of HH.
I also wonder why these balls were not cast for Heinrich's father, JULIUS (1528-1589) as his living period is more consonant with this ammunition date. Their titles are almost the same, but the father has no HEINRICH in his name.
Amazingly the German auction text only mentions JULIUS and, unfortunately, the translating engine is not exact on what touches some vital parts of it.
It is also interesting that Michael mentions that the ball is cast of iron-slag; in fact it weighs much less than an ordinary iron ball with the same diameter. Why were these balls made with iron-slag ? not certainly for economic reasons but, there must be a reason for that. Could it be that iron-slag is a better splinter when hitting the target ?
Anyone here willing to help me better understand this whole situation ?

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