During WWII the Allies really made quality firearms. Those 40's era weapons are still around, and many of them perform as good as the day they were made. The true test is in a recent unearthed Browning machine gun (from a Spitfire) that spent the last 70 years in a bog. The weapon was cleaned up, brought to the range, and it still fired! Check out this quote via Liveleak (small edits made for continuity sake):
November 1941, Roland 'Bud' Wolfe crash landed in Inishowen, Co. Donegal. His plane's coolant overheated during a patrol mission just north of the Inishowen peninsula. Trying to return to RAF Eglinton, he had no choice but to bail out of his Spitfire, as he was losing altitude. His plane crashed in the heather covered area of Moneydarragh, Gleneely. He was arrested and sent to Curragh detention prison, where he spent two years. He was then released and went on to serve the 'Eagles' once again.
With the help of the Irish Army, the Spitfire was recovered along with six Browning Machine guns, and over one thousand rounds of ammunition on the 28, June 2011 by aviation historian Johnny McNee. The recovery was filmed, and will be made into a documentary for the BBC.
The first clip is all the cool action stuff, and the second clip shows the boring digging.