Without a composition analysis there is no way to know the steel used for the barrels; but it is very unlikely to be nickel steel or 4140 chrome moly.
There has been lots of discussion about using steel in vintage barrels, esp. from England

https://www.thefield.co.uk/shooting/steel-shot-and-vintage-guns-45758

https://www.shootinguk.co.uk/guns/ammunition/steel-shot-in-old-shotguns-126432/

Current steel shells have thick shot cups to protect the barrels, but, other than target loads, are loaded to very high velocity with substantial recoil, and the risk of cracking the head of the stock.
Certainly you will need to have the full choke opened in order to use steel.