Thanks for posting that website Suther (they have some nice looking stuff and good reviews).
Perhaps the OP should look into shotguns that can actually handle the loads he wants to shoot (or in the future wants to shoot) as it is a concern noted on some of the adapters.
Quoted from Chaszel's website(direct copy I did not clean up the grammar/spelling):
"...Therefore only use these rounds in shotguns that are capable. For example, a shotgun with a SB1 or Sb2 reciever. I recommend on any shotgun to test the first shot in a vice while out of harms way in addition always wear eye and ear protection. After that if you see that the primer punctured in the round discontinue using this round and use the less powerful round. Such as a 38 Special instead of the 357 Mag These high pressure rounds include: 45-70 Shotgun Adapters., 357 Mag, 327 Shotgun Adapters , 44 Mag, and 22 Hornet. Please always be safe and aware..."