I was sitting by the the fire(small barrel). I was planning to put some bullets inside the barrel, to destroy it and by accident I switched my akm(with suppressor) with the backpack in the fire barrel. I noticed it very quick and took the akm back, but the suppressor was missing. I clipped and watch it back, the moment akm went into the fire barrel, the suppressor vanished in 2 second.

The map was Sakal, the location was the last military eiland, before the bunker area you have little military base with many cargo containers and barracks. The fire barrel is inside the red brick, towards the light house.