Is vacuum sealing safe? I'm a total newb, never touched a gun.

I just found out yesterday that you can cause misfires or cause your gun to explode by re-chambering the same bullet too many times, because of the bullet getting pushed back into the case and messing up the density of the gunpowder, or the firing pin tapping the primer and messing up its density, etc.

So is it safe to vacuum seal it and that won't mess with the density of the powder?