Help! Loading slugs,

[Bug]

I borrowed a mold for 20ga foster-type slugs, and fixin' to get ready to load. I have applicable data, but with a SNAFU! The slugs don't fit! They are a nominal 0.595" outside diameter. Bore at muzzle of gun is right at 0.600". The slug will drop through the barrel with no problem. Thing is, there's no room for the 0.025" thick wad petals. And the I.D. of the wad, at the base of the petals, is about 0.510". Ain't no way it's gonna all fit! The slug is a fair slip fit in the AA hulls I wish to use, slightly looser than a wad. What have I failed to consider here? Surely, the wad petals ain't supposed to fit up INSIDE the foster's hollow base, are they? What gives, guys? >>>>>>>>>>>>>>>>Bug.

[Bullseye]

I am not an expert on this, but I do not think that Forster type slugs use wads with petals.  They just have a plastic cup between the powder and slug.  Remington brand slugs will pass through the bore, Winchesters I think are a little tighter.

[Robert]

The Lee Key slugs are smaller and fit into a shot cup.  I have an old Lyman 12 gauge mold, and it is also just a tad loose in the bore.  I haven't gotten too fancy with equipement for loading these yet, so I have made do with what I have around....and yes..I did load some with the wings tucked inside.  I cut the wings off flush on some too, so they resemble the wads that are normally in commercial slugs.  But the most fun I have had with them is with an old black powder 12 gauge, and using some old fiber wads for loading the old style paper shells. These wads have been sitting for years and have swelled up, they won't fit in shells anymore, but they are excellent for wads in my cylinder bore muzzzle loader.