Steve- considering Foster-type slugs as Benneke's as well as others lke Gulandi for instance, are designed with collapsing ribs that allow them to be fired through full choked barrels- without damage. This leads me to think perhaps the old Husky shotgun's barrel steel is not made from stern enough material for these loads.
Modern powders and loads, although not producing much, if any higher pressure than black powder loads produced at peak, does produce that pressure over a longer period of time - ie; farther up the tube and that is the reason many old guns will let go- about where you hold them, due to rapid tapers - or thinning due to risky re-chambering, mostly.
Since the gun noted by Steve blew the choke apart, this pretty much speaks to the material itself and the suggestion of opening up the choke first, is a good one, as well as not using high pressure ammo of greater length or strength than the gun was originally designed.
The rolling block actions, if the same as used on their rifles, are sufficient to accept any 12 bore load, but the original barrels seem not to be a good choice for such a venture.
Modern powders and loads, although not producing much, if any higher pressure than black powder loads produced at peak, does produce that pressure over a longer period of time - ie; farther up the tube and that is the reason many old guns will let go- about where you hold them, due to rapid tapers - or thinning due to risky re-chambering, mostly.
Since the gun noted by Steve blew the choke apart, this pretty much speaks to the material itself and the suggestion of opening up the choke first, is a good one, as well as not using high pressure ammo of greater length or strength than the gun was originally designed.
The rolling block actions, if the same as used on their rifles, are sufficient to accept any 12 bore load, but the original barrels seem not to be a good choice for such a venture.
