Marcinkiewicz 303FL vs Marcinkiewicz CH BSC FL
The Marcinkiewicz 303FL has a wider cup diameter, the Marcinkiewicz CH BSC FL has a larger throat opening.
Cup Diameter
The Marcinkiewicz 303FL has a cup diameter of 17.20 mm / 0.6772 in compared to 16.74 mm / 0.6591 in on the Marcinkiewicz CH BSC FL — a difference of 0.46 mm / 0.0181 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very shallow cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Marcinkiewicz CH BSC FL has a wider throat (4.39 mm / 0.1728 in vs 4.32 mm / 0.1701 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Which is better?
Neither mouthpiece clearly dominates the other — the right choice depends on your embouchure, playing style, and the sound you're after. Try both if possible.