Please, I asked on the shotgun section but

no answers yet; what are the factory spec.

dimensions of a 3 inch 20 gauge shell: rim

thickness, rim diameter, base diameter?

Thank you.

Jack sorry just a 2 3/4 - dimensions are in mm:

Got it :



G max = 19.40 mm, tolerance -0.20 mm
D max = 17.70 mm, tolerance -0.15 mm
T max = 1.55 mm, tolerance -0.20 mm
H max = 17.35 mm, tolerance -0.25 mm

Thanks much M93!