The regiment was disbanded by invading German forces after the announcement of the Armistice of Cassibile on 8 September 1943.

The regiment was assigned to the III Missile Brigade, which consisted of the Italian Army's units with a nuclear weapons mission.

The US Army's 559th Artillery Group stored the W31 nuclear warheads for the regiment's battalions at four sites in Northern Italy.

In 1974 the regiment was reduced to a single group, which was re-equipped with MGM-52 Lance tactical ballistic missiles.

The same year the group was reorganized as 3rd Heavy Artillery Regiment "Volturno" and equipped with M270 Multiple Launch Rocket Systems.

[1] This article is about the Royal Italian Army's 3rd Heavy Artillery Regiment, which was a support unit assigned to an army-level command.

The regimental depot formed the commands of the 8th, 13th, 18th, 22nd, 24th, 61st, 63rd, 64th, and 70th siege groupings and the commands of 26 siege groups: VII, X, XVIII, XXIII, XXX, XXXVII, XXXIX, XL, XLI, LXIV, LXVI, LXIX LXXXI, LXXXIV, XCI, CXLII, CLII, CLVI, CLXV, CLXXIII, CCXIV CCXV, CCXXVI, CCXXXII, CCXXXIV, and CCXXXIX.

By January 1923 the regiment consisted of a command and four groups, which fielded a mix of cannons, howitzers, and mortars.

In November 1936 the regiment formed a Marching Position Artillery Group, which was sent to Massawa in Eritrea to provide replacement personnel for units engaged in the war in Ethiopia.

The depot was disbanded by invading German forces after the announcement of the Armistice of Cassibile on 8 September 1943.

On 10 January 1959 the first 44 Italian soldiers began the training to operate MGR-1 Honest John nuclear-capable surface-to-surface missiles at the US Army's Caserma Ederle in Vicenza.

On 25 February 1959 the Italian soldiers launched their first Honest John missile from the training range at Bibione into the Adriatic Sea.

On 1 September 1962 the XV Heavy Artillery Group joined the III Missile Brigade and took on a nuclear weapons mission.

On 1 January 1966 each of the regiment's four groups received a fusilier company tasked with guarding the Honest John launchers.

[6] In 1967 the US Army build four smaller nuclear warhead depots closer to the groups of the 3rd Missile Artillery Regiment:[7] In preparation for the introduction of the MGM-52 Lance tactical ballistic missile into service the regiment's I and IV groups were disbanded on 31 July 1973.

Afterwards the XIV Heavy Artillery Group moved from Trento into the empty base at Elvas.

On 26 August 1974 Italian personnel arrived at the United States Army Field Artillery School in Fort Sill to start training on the Lance system.

The next day the group entered the reformed 3rd Heavy Artillery Regiment "Volturno", which was assigned to the 5th Army Corps.