The Trinity College graduate's co-accusedS, John Troy (33), John McGreal (36) and Colin Brady (23) were also granted bail. Brady of Ashgrove, Baskin Lane, Kinsealy, did not take up his bail.
The charges against the four include the unlawful possession of one 9mm parabellum calibre Taurus PT92 semi-automatic pistol, one magazine suitable for use with the Taurus PT92 pistol, one 9mm parabellum calibre Walther P5 semi-automatic pistol and one ZGJY branded stungun and flashlight.
The four are also charged with the possession of 25 rounds of 9mm ammunition and seven rounds of 9mm ammunition.
McGreal, of Thornchase, Palmer Road, Rush, and Troy, of Dunard Avenue, Cabra, are additionally charged with membership of an unlawful organisation within the State styling itself the Irish Republican Army, otherwise Oglaigh na hEireann, otherwise the IRA.
Shannon, along with Troy and McGreal, signed €100 bail bonds on independent sureties of €20,000 each yesterday, along with a number of other conditions.
These included signing on daily at their local garda stations, surrendering their passports, not going to Co Offaly, not associating with their co-accused, not associating with any person convicted or charged with a scheduled offence, not leaving the jurisdiction, not contacting any proposed prosecution witnesses, keeping their mobile phones on at all times, and being of good behaviour and keeping the peace.
They also agreed to individual curfews. Presiding judge Mr Justice Paul Butler, sitting with Judge Margaret Heneghan and Judge William Hamill, granted bail to Brady on similar conditions.
The court previously heard that Shannon and McGreal were arrested two days after the alleged offence on Kilbride Street, Tullamore, Co Offaly, while Troy and Brady were arrested on College Street, Mullingar, Co Westmeath.
None of the accused made any reply either upon arrest or when they were charged.
They are all due back before the court again on February 5.