I mean, it's possible. Tamp too much and compact the tobacco. But has to be rather stupid to tamp that hard. It's also possible to get tobacco stuck in draught hole some where. Pack like an idiot? Also possible. But have you ever had perfectly smoking pipe suddenly won't let you draw? Happened to me today. Bone dry VA that I forgot to pack. Loaded up today, did draw test like I always do. Went out and it was smoking great. Then towards bottom 1/4 bowl, nothing. No way to get anything out of the stem. Took the stem out, cleaned stem, mortise, dry out pretty good, run the cleaner to the chamber. Put everything back, still no draw. Weird. Poke some hole from top of the chamber, nothing! How crazy is that? Dumped everything thinking something must be really wrong. I mean Newminster 400 that's been drying for over 24 hours in a pipe that smoked fine last time. What can go wrong? All the remaining tobacco was crumbled, and wet. Solid block of it was blocking the entire bottom of the chamber. I didn't see it at first. Ran the Czech tool, dump the content, but seemed like whole thing didn't come out. Had to dig harder, and the wet chunk came out. But out of 24 hr dried Newminster 400? How that possible? I'm not a wet smoker, if I was I would have seen something similar before. Just a crazy day.