Y-Man Needs Help With New Slug Design

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.

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
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…)

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Mike

    I do not know the current dimensions of any Foster type slugs. They vary from manufacturer and from to a degree, from each manufacturers mold and production lot. Keep in mind that the “rifling” on Foster type slugs are actually designed to be crushed under the constriction at the choke tube. They do not serve to “spin” stabilize the slug. They provide a means to keep the slug aligned while the slug passes through the choke without deforming the overall shape of the slug.

  • Seamus

    Y-Man is a boss.

    • Nanban Jim

      And it’s FANTASTIC to see something from him again. Was worried after a while!

    • Will

      I’m game! Who is in contact with Y-Man? Lets get together and ship him a care package.

  • Raoul O’Shaughnessy

    I love this guy’s attitude and ingenuity…BUT…can’t we just pass the hat around and mail him a couple Lee moulds and maybe a Lyman sabot slug mould?

    • Will

      I’m game! Who is in contact with Y-Man? Lets get together and ship him a care package.

  • Maximus Hypicus

    .685 Dia +/- .003

    .625 Length +/- .003

    Lee foster mold

    .735 Dia

    .635 length

    Remington rifled slug

    • Thanks Maximus!

      • Maximus Hypicus

        No Prob!

        I would go insane if I couldn’t play, study, own, or create ammo.

        I’ve watched his posts from the beginning.

        Any help I can give a fellow ammo tinkerer, I don’t mind at all.

        Hope It helps

  • Chris b

    We done!

  • bbmg

    Keep centre of gravity and centre of pressure in mind.


    In order to fly straight without the benefit of gyroscopic stabilisation, the Cg needs to be forward of the CP. There’s a bit of maths involved but it’s not too complex, better than wasting your time on trial and error.

    Hard to tell if the slugs illustrated conform with this requirement.

    Alternatively, consider permanently attaching the wad to the base of the slug, this will act as a drag stabilising tail and keep it pointed head first.

  • The things free people can do…

  • gunslinger

    i was beginning to wonder what happened to y-man

  • Jesse

    I love this guy’s attitude. He is the kind of guy you want next to you if your town gets invaded by zombies. He’s fricking MacGuyver.

  • Y-man

    Hey guys! Many thanks for the care and concern. Thanks for the kind words also…

    Ummmm, not sure about any “care package”! Could get me “whisked’ away and locked up (If not worse) as a “terrorist mastermind”!

    Many thanks, anyway…

    Looking forward to some range time in Orlando FL on vacation in October! Yay!

  • Nicks87

    Y-man you kick ass bro, keep doing what you’re doing!