Ely VIP Bismuth cartridges are available in UK in 65mm chamber length, felt wads and 32 gm No 4 shot; there are other load / wad combinations too.

I shot some last week through a lightweight 2 1/2" Brummie box lock with no problem at all; certainly not a firecracker load. I didn't shoot anything much beyond 35 yards but with 3/4 choke ducks dropped dead.

If they are available in Canada or the US they might be worth a try.

Eug

Thank you, very kind. Mine's a pint