You can use your bird barrel with interchangeable choke tubes to shoot Remington Sluggers, or any other lead type Foster slug.
While results vary from gun to gun, most of the time, the more open chokes will give the better results. For example, Remington makes their smoothbore slug barrels with an improved cylinder choke, Winchester makes theirs with a cylinder choke.
The more important question is,' do I have the ability, or option, to ridgidly mount a set of adjustable iron sights or a scope on the gun'. If you do not, it's almost a moot point to bother. Attempting to aim with the single shotgun bead will give dismal results at best. And at least in my state, you cannot hunt deer with a shotgun using slugs, unless you have either adjustable iron sights, or a scope on it.