I picked up a 1991 Browning BPS in 10 gauge. It currently has a Browning Full Lead Shot Only choke, so I cannot shoot it as I only have steel shot loads. A Modified (Lead) Full (Steel) choke tube is on its way to me. Do you have a recommendation for slug/buckshot loads? Also, should I get an IC choke for shooting geese?

Typically I would suggest our Boar Blaster® choke for large diameter buck shot. However as we do not make this in the 10 ga. I would then suggest an extended full choke.
For slugs go with an open choke such as skeet or imp cylinder.
Normally (at least with our chokes) an extended mod choke with large dia. steel shot is going to give a full or extra full pattern.
if you will be shooting geese in the 30/35 yard range then go with the imp cylinder choke.
George Trulock

Thanks for the advice.