you used recored SV98 shot-sound?
You can hear that at the slow mo part when you shot you hear at the sound also the shot, but in video you go slow-mo and the shot sound directly is followed by the
sound when pulling back the ball that will empty the chamberroom and makes space for a new bullet.
so
at the slow mo part:
video:shoot, audio:shoot
*getting in slowmo*
video: pulling back that little ball audio: no sound because the sound after the bullet is already played in slow mo,
so work on it.
/most horrible explaination ever