I'm flying into OR Tambo in Jo'berg in March and am due to land at 0750 local. I need to get a connecting flight over to Cape Town and am thinking of booking the 1250 BA Flight.

Is 5 hrs sufficient to negotiate immigration (I've flown into Jo'berg a lot and know it can be bad - just never needed to make a connection), collect baggage, recheck and pass back through security for the Cape Town flight?