Can I shoot a slug thou my sweet sixteen?

You can shoot slugs through a Browning Sweet Sixteen, but not sabot slugs, as they are intended for use in shotguns with rifled bores.  The choke should not matter, although improved cylinder would be the most ideal choke.  

However, a choked shotgun barrel is not the best barrel for slugs.  (A) A barrel that is cylinder-bore choke (essentially no choke) will give the best results  (B) Firing a few hundred slugs or more through a choked barrel will eventually damage the choke.

slugs such as brenneke and foster (european and USA) can be used through ANY choke as they have grooves cut in them to swage through the choke and are hollow based. However British slugs are solid and do not have grooves and should only be used in rifled choke or fully rifled guns

i wouldnt do it

Date made 1967 sweet sixteen in a one shape