Y-Man Needs Help With New Slug Design

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Y-Man, TFB’s favorite Nigerian shotgunner, needs some help with measurements for his new slug design. Read about Y-Man’s previous adventures here.
VIDEO
Y-Man says …
I have been a bit slow with my shotgun stuff recently, but have been doing a lot of research. I now have a slug that has VERY good promise now, I got a very good mould fabricated and am using the idea behind the Federal Truball Slug design …
Federal Premium Tactical TruBall Shell
My own (new) version of the Truball Slug
VIDEO
My slug with ball, wadding and shell
It WORKS! I am getting good groups out to 45 yards too! But unfortunately, have not been able to do much testing. I did do some testing in April, and while the groups were good, my improvised shotgun sights were crap, and led to me shooting about a foot low at 45yards. (I was shooting quite rapidly though, did not really take careful aim (Once I saw that my sights were hopeless. I have gone back to a simple barrel-aligned sight now.)
Please do me a favour: if you have any factory produced Foster-type slugs lying around (Like the Lee slugs) could you help do a measurement so I know if my measurements are ok?
What are the REAL dimensions of the factory-made Foster-Type slug? (I have been working blind all these years: I should have used some sort of reference measurement…)