coming back to punt guns,

http://xtremeidaho.com/wp-content/uploads/sites/10/2014/11/PuntGunWeb-e1416899154106.jpg

http://www.tigerdroppings.com/rant/outdoor/punt-gun/60981529/

cartridges for punt guns is one my interests and I still looking for some of them
http://municion.org/ having some informations about
I am not sure about the american made 1 ga and 3 ga paper shells, they are very short and I have never seen a breech loading punt gun chambered for them but maybe someone her knows more about. I believe they were made for saluting cannons what was very common still after WW 1 especially on yacht's.
imho, punt guns were banned in the united states before the advent of breech loader.

1 ga

3 ga

the most common chamber was the 1 1/2" cartridge

http://www.warstuff.com/Scarce-Inert-English-4-Bore-Punt-Gun-Brass-Windo-i1555726.htm

here in the 1904 eley catalog

the 1 1/2" shell was adopted by britain for signal flare pistols in the great war when the the common 4 ga was not enough anymore. this way it still exist as the 37mm , sometimes called 38 mm case for tear gas grenades and similar special stuff. I think its still possible to use the 37 mm case in old punt guns.

1 1/2" Eley 6" long made in the 1970s, 37 mm case 8 " long, 4 ga plastic case, different 26,5 mm signals flare cases

the 32 mm or 3ga punt gun cartridge was made in France and Italy and was probably used only there

here in the 1926 Fiocchi catalog

this Fiocchi catalog is also interesting because it having two different 4 ga and 8 ga shells, a british and a french version

there is no other reference for a special french 4 ga and 8 ga shell. iirc, the only thing is that french signal flare ammo in the great war was not fit in german pistols but german made 26,5mm signal flare ammo was fit in french pistols . when I compare the french 4 ga dimensions here with the british 4 ga it looks like a halfway between this and the german 26,5 mm signal flare cartridge.

british made signal flare pistols are chambered for the common 4 ga 4" long shotgun shell at least up to 1945.