I've got a 58mm Motta, there is a tiny bit of wiggle room in the basket...
Using a Mahlkonig Vario, not getting clumps AFAICT but I haven't broken the grind up in the basket after I dose for ages... It looks pretty good and unclumpy... I tap the coffee level before tamping...
until I changed my shower plate I used to get really inconsistent flow through mine which led to a lot of channeling/spurters - the IMS precision screen helped a lot. still get the occasional messy shot which I can't nail down but that also helped a lot.
I've got a 58mm Motta, there is a tiny bit of wiggle room in the basket...
Using a Mahlkonig Vario, not getting clumps AFAICT but I haven't broken the grind up in the basket after I dose for ages... It looks pretty good and unclumpy... I tap the coffee level before tamping...