Have a Mosin and a 5rnd Clip.
With Mosin in hands, use the reload key.
Listen to the sound bug.

It sounds as if it is replaying the sound for each bullet in the clip, whereas it should only be playing it once.

So basically its as if each bullet is causing the sound of 5 bullets being loaded being played 5 times simultaneously.

Solution: Check number of rounds in 5rnd clip, and use the same audio as if you were to manually drag over a stack of bullets.