I hear that once in a while and yet I've never experienced it....geeze....in 40 years of using the same Forster. Somebody's in too big a hurry. I fit the base into the collet, then slide pilot into the case until the cutter shaft stops, and THEN and only then do I tighten the collet.
These days I am a bit more impatient using a progressive and all, so I added the 3-way cutter, a power adapter, and most importantly, mounted it vertically so that gravity (with help from a weight) drops the shaft tightly against the case. Accuracy has been nearly perfect...+/- .001"...good enough for my needs. In the video below, the first case was about the worse problem I've seen. The pilot hung up for a second on a burr, but obviously the collet wasn't tightened finally until it slipped in, and the shaft came down tight.
Click picture for a video of the Gravity-Fed Forster with a 3-way cutter....trims, chamfers, deburrs! Notice the smoothness of the tool. That's how a quality-machined tool gets accuracy....if the operator does his part. Wilsons are quality as well, but overrated for large batches of cases to do. If I bought one now that I load progressively, I'd be going backwards. They are too slow and not any more accurate IMO if you use undamaged brass. I don't load any other kind.