Gareth Bryer, who runs the Youtube channel Drasticg, often goes magnet fishing in a bid to clean the waterways of all the discarded metal and plastic rubbish.
During a trip over the weekend in Saddleworth, Manchester, the explorer made a startling discovery.
In the clip, Gareth begins by trying to pick the weapon up off the bed.
After swapping to a double-sided magnet, he manages to attract a metal object and pull it up to reveal a handgun.
Gareth said: “Oh, it’s a handgun.
“It seems to be metal but it took a while to get onto The magnet.”
After pulling the item up, Gareth revealed a brown handgun.
He added: “It’s a BB gun.
“Normally they paint the BB gun orange because they can’t paint them black anymore because the police think they’re real guns.”
While using a cloth to handle the weapon to have a look, he added: “It’s quite corroded but looks like it was orange originally and somebody’s tried to paint it gold.”
After uploading the clip of his discovery to YouTube, close to 25,000 people have viewed the clip.
Gareth detailed that he usually fishes for trout in the lake but, for a change, he decided to go magnet fishing.
One person said: “Well done mate great find.”
Another said: “This is brilliant.”
A third said they believed they saw a second gun in the water.