Got a Gaggia Classic for Xmas, and found a Mazzer mini on sale for $550 shipped. Worked with the Gaggia for a few days using the high pressure basket (single .6mm hole) and had some decent shots.

Got the Mazzer yesterday, spent about 2h trying to zero in on a good grind consistency and have not been able to pull a decent shot to save my life. I'm getting 2oz of shot in at about 20s, and the first liquid starts to flow at the 3-4s mark. I'm thinking maybe it should take a bit longer? When I'm done the basket/puck is soupy. I've tried to make the grind finer, but it ends up completely blocking up. I'm guessing my grind consistency is correct but maybe I'm not tamping hard enough? I've been going pretty light on the tamp because I'm afraid of overdoing it.

I'm looking for some suggestions on what to tackle first and how to best work with all of the variables at hand. I don't want to keep adjusting grind consistency when it could be a tamping problem. I don't want to over tamp if it's actually a grind problem, etc. Luckily (??) the Gaggia has a preset temperature / pump pressure so I don't have to worry about adjusting those (right?).

Cheers!