Oh yeah, I know that one well!
Rented this huge towable auger one time here, and it jammed every 2 inches due to this land being pure red clay with golf ball sized rocks. At one point I was hanging from the lever, digging for 10 seconds, then using a scraper on the blades for 20 seconds. Took 12 hours to dig 10 holes!
I use a shovel now. It never jams up, and my arms get a free workout.