hey i just recently came up with the idea of have a combat patrol of the ultramarines 1st company for a combat patrol
here is my list

Tyranid hunters (5)
heavy bolter 10

Tac squad 1 (7)
apothecary
heavy bolter

Tac squad 2 (7)
apothecary
heavy bolter

Traits
can't remember the name but one gives the squads apothecarys and the other lets them have prefered enemy