ACE is not a federally owned "postal property".
http://www.gpo.gov/fdsys/pkg/CFR-2009-t ... c232-1.pdf" onclick="window.open(this.href);return false;
§ 232.1 Conduct on postal property.
(a)Applicability.
This section applies
to all real property under the charge
and control of the Postal Service, to all
tenant agencies, and to all persons en-
tering in or on such property. This sec-
tion shall be posted and kept posted at
a conspicuous place on all such prop-
erty. This section shall not apply to—
(i) Any portions of real property,
owned or leased by the Postal Service,
that are leased or subleased by the
Postal Service to private tenants for
their exclusive use;
..........................
(l)Weapons and explosives. Notwith-
standing the provisions of any other
law, rule or regulation, no person while
on postal property may carry firearms,
other dangerous or deadly weapons, or
explosives, either openly or concealed,
or store the same on postal property,
except for official purposes.