Mitchells mausers refurbishes rifles, good shooters but pricey. As far as I know bolts were blued, that is how I've known the Kar98. I've seen a handful of period rifles with chromed bolts but they were parade rifles.
When I die better bury me deep, two .45s layin' at my feet,
An M16 across my chest, tell Chesty Puller I did my best