Question

what is prohibited bore

Answer 1

The Arms Act defines “prohibited arms”. Arms which are automatic or semi automatic in nature fall in the category of Prohibited Bore (PB) arms and the remaining arms which are non automatic or bolt action type are covered under the category of Non-Prohibited Bore (NPB) arms.

Answer 2

the arms act defines prohibited arms. arms which are automatic  in nature fall in the category of prohibited bore arms and the remaining arms which are non automatic or bolt action type are covered under the category of non-prohibited bore arms.