Me too, i am confused.
Sprinting + weapon in hands (sks) + suddenly stop (block by a fence, wall..) or go prone = auto Throw weapon
Sprint with weapon in hands (sks, cr527) + go prone = 95% effective, to reproduce the bug.
And at the first times to play this ver. of exp (i cant reproduce now) when you are stopped and have the primary weapon (sks, and splitting axe) in hands if you go prone, the character go prone and inmediately go stand up and auto throw the weapon.
Wiffel: I never lost the weapon, you have to look better, if you are on inclined terrain, the gun can roll downhill... provided it do not fall under a pine tree or crosses the floor of a buggy house...
ver: 47.124531