Section 155 of the Principal Act is amended by omitting subsection (4) and substituting the following subsection:

(4)  The Commissioner, subject to any specified condition, may exempt a person or class of persons from a provision of this Act relating to the possession or use of any or any combination of the following:

(a) any ammunition;

(b) a firearm;

(c) a firearms magazine;

(d) a firearm sound suppressor.