Unknown american case

it is a 38.8 x 23.5R straight brass case
The primer is the same as for the 1.65 (42 mm) Hotchkiss Mountain gun

Dimensions are :
Length : 235 mm
Case mouth diameter 38.81 mm
Case neck diameter : 40.31 mm
Case base diameter : 46.48 mm
Rim thickness : 2.24 mm
Rim diameter : 51.13 mm

The hstp is : Winchester RA Co Ne Haven CT US

Is it for a 1 Gauge Hotchkiss yacht canon ??



This is a propelling charge for the 2.5" Sims-Dudley “Dynamite” Gun.

thank you Fede.
This case is not mine, it was part of the collection of a very nice guy of IAA living in Arizona who was a very big collector of big bores.
And he was always wondering for which use it was.
It is a shame he is no more there to have the answer.