machines are immune to mind influencing psychic effects.

would that mean they are fearless and have nerves of steel?

Both of those talents refer to pinning tests, not psychic abilities, so no they do not get them for free.

Also note it says Mind influencing psychic powers. An enemy psyker using smite would still kick the crap out of a techmarine.

so you can scare and pin battle servitors?

Technically, a battle servitor would indeed suffer from pinning tests, yes. A rational reason for this might be the machine spirit within the servitor knows better than to stick its head out and die worthlessly in hail of gunfire.

vogue69 said:

Yes use your discretion for that, one of my players had some questions about that and I told him as far as possesion goes your good, but does not mean if a psyker makes and illusion you instantly see past it ect. Also immunity to possession does not mean immunity to corruption or insanity.

vogue69 said:

No. It gives exactly what it says, immunity to mind influencing psychic effects. Fear and pinning do not fall into that category.