I saw this on the BBC & read the story online before. Although it is regarding WWII & a Spitfire:
Archaeologists working up in Donegal excavated a Spitfire that had crashed into a hillside bog back in 1941, after encoutering a mechanical failure. Despite crashing at around 300mph the soft bog land acted pretty well as a cushion so that some parts of the plane survived relatively intact. Also the clay and peat acted amazingly well at preserving the articles including the paper manual and the 6 browning machine guns. Because these were considered ordinance and still had full belts of ammunition the Irish Army was called in.
One of the Irish officers, Lt. Col Sexton looked at the relatively intact guns and had a 'crazy idea'. He retrieved and cleaned the best preserved parts from the 6 guns, put them together into one, 'straightened out' a few bent bits and decided to fire it off to see if it worked. The video is in that clip.
Incidentally the Spitfire that went down was being flown by an American volunteer to the R.A.F. called Roland 'Bud' Wolfe. All this lead onto one of the more bizarre episodes in The Emergency here. Because he came down in the Free State, Bud was interned in the Curragh, Army Camp in County Kildare. Security here was lax to say the least and Officers like Bud were given free reign to move about upon the honour of their word. Very soon after arriving in the Curragh, Bud simply walked out, had dinner in a local hotel and jumped a train to the North and on back to his squadron.
The Irish Government complained to the British that this was ungentlemanly and unfair as he'd given his word not to leave and amazingly the British agreed, arrested Bud and sent him back. He tried to escape again but was caught. In 1943 the Irish shut down the Curragh internment camp for WWII prisoners and just sent him and the rest of the Allied interns back.
http://www.bbc.co.uk/news/magazine-15652440
http://www.omaha.com/article/20110710/NEWS01/707109941/-1#spitfire-s-pilot-was-a-fighter
Truly amazing to see that gun in action again nearly 70 years later.