Thanks Gert,
yes I use .44 Caliber Gas Checks myself for cast bullets in my .404.
I have sufficient at present, definitely not have a lifetime supply of these like Homer as we don't get paid all that well in the Electrical Industry!
I can't remember the actual make of mine but got my .44 GC's off Cast Bullet Engineering here in Oz.
They were rather hard & didn't size too well at all until I got a mate's missus who has a kiln to anneal them (packed them in mint tins) - much better after that!
It seems silly that GC's aren't made for the .404, but considering the numbers of .44's out there & the closeness in size you can understand why they don't.
Guess it takes someone like you to get pissed off enough to get off their backside to actually do something about it - best of luck there mate!
Keep us all informed here mate as this is really the central hub for this side of things!
There certainly will be someone interested soon enough.
Hope that helps
93x64mm