Curry 7 P vs Kelly 7C
The Curry 7 P has a wider cup diameter, the Curry 7 P has a larger throat opening.
Cup Diameter
The Curry 7 P has a cup diameter of 16.56 mm / 0.6520 in compared to 16.51 mm / 0.6500 in on the Kelly 7C — a difference of 0.05 mm / 0.0020 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Curry 7 P has a wider throat (3.70 mm / 0.1455 in vs 3.66 mm / 0.1441 in). A wider throat allows more air through, increasing volume and projection but reducing resistance.
Material
The Curry 7 P is described as unspecified, and the Kelly 7C as Lexan polycarbonate. Material affects mass, warmth, and how quickly the piece responds.
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.