I ran my first OW game the other day, and the players had a Chimera.

The vehichle comes with about three heavy weapons. No one in the squad had the Heavy Weapons Training talent, but it was clear to me that all of them (especially the Operator) would be disappointed to realize that they were not going to be able to use their tank efficiently, so I winged it. It was, after all, a one-shot.

But am I correct in assuming that according to the rules, a heavy weapon is always a heavy weapon and Operators are ill-adviced to not learn how to use them?

Only War, core book, p. 274, second-to-last bullet point, first column:

A character with the appropriate Operate Skill for a vehicle does not need specific weapon proficiencies to fire any weapons mounted on that type of vehicle without penalty. It is assumed that his expertise covers weapon use as well

So no.

However, this rule is sadly deeply burried in text and not easy to find.

Excellent.

I would not have found that. :-) Thanks.

Excellent.

I would not have found that. :-) Thanks.

For such an important rule, it sure is burried deep, I think.