I roll size and use a U-die for 9 mm major.. Everything fits perfectly in my Hundo gauge. In one of my open guns, anything that passes the gauge will plunk. Unfortunately, I recently learned that that is not the case with my primary match gun. Same barrel type, same gunsmith. Match ammo gets plunked individually in this barrel. Rejects go into the practice bucket.
Long story short, the gauge is only a guide. If it doesn't plunk in YOUR barrel, problems arise