PM, the shells made up for the gun are 2 1/2" now that I look closer at them.
Maybe I was mistaken on the chamber length...
Well, the chambers are 2 3/4" as stamped on the underside of the barrels. Thought that was the case.
So, a couple questions may be: are the 20 bore Paradox shells always 2.5" even in a gun chambered for 2.75" shells? Is the 2.75" chamber length to utilize the more powerful 2.75" 20 bore shot shells while keeping with the 2.5" paradox shells?
I can't find any record of a 20 paradox cartridge using a case longer than 2 1/2".
The Holland loadings were 18 and 20 grains cordite and 1 gun regulated with 25 grains.
Certainly there were 20 bore shotshells at 2 3/4 and 3".
There were only 27 Holland 20 bore pdxes, probably less than 100 Faunetas and the other makers? Not many.
Be nice to get your bore dimensions.
Proofs on a couple of Faunetas showing the 2 1/2" (no LC)