Over powder wad....?

[Mossy88]

I read that cork is a good material for over powder wads.
Not looking for 'best' here...just figuring out what works.
The loads will be low end mild pushing about an oz of lead out of a 12 gauge @ maybe 1100 or 1200 fps.

edit..as a side note..I bought an 18mm punch. perfect fit for wads inside a 12 gauge shell

[faustus]

"Modern" loads normally use a wad with an integrated gas seal .... or a separate gas seal.

Have a look here ...

https://www.ballisticproducts.com/Gas-Seals/products/97/

[zarrinvz24]

I’ve had good luck with ceiling tiles as a cushion wad. For over powder wad I like to use a thick cardstock, almost like a cardboard. It is easily found on the back of legal pads of paper or the desktop calendars that frequently are thrown away. I put a thin disc of paraffin in between the two to aid in gas seal and lubrication.

[zarrinvz24]

I assume you are using brass shotshell?