I've not long dumped a heap of spent 12g carts, mainly eley olympic blue.

I'll take better care of the next load I generate, likely to be a mix of fiocchi TT1's (67mm, that work well in my 3" chambered 525) and Eley Olympic Blue (70mm).

I've never re-loaded 12g, but I've been reloading .410 this last while and whilst these 12g carts aren't fancy high brass cases, IMO they'd take a reload especially if reforming the crimp on a press, but then I'm unsure of the type of original crimp on the TT1, because I don't have any left to check, the blues are a 6.

So if those are any good to you, let me know and I'll save what I can.