I got some blank carts the other day and they don't fit my Atomizer where the mouth piece goes in the Atty. The are there right carts for my atty. If I get them in then I need a really strong man (Hercules would do) to take them out.
Just wondering if you could use a razor and shave them off a bit to fit, or a piece of sandpaper.
I use an 801 too, and I've had the same issue, and took the filler out with tweezers and put into a cart I knew fit.
I never thought of this til now, but I bet you could get it to fit...just a thought....