It is vague however there is pretty specific verbiage on the intent
(The intent of these rules is to establish a match for common hunting
carbines and other lever action rifles. The match is focused toward shooters who
enjoy shooting hunting arms and do not want to make the investment required of
other specialized types of shooting competitions.)
A person could in theory re bore a Marlin to 7/30 Waters use spritzer bullets pushed into the magazine before each shot then chambered with the lever and gain some advantage. Lot of other ways to tweak too, many that are controversial, look at all the upset about Fiber optic sights. What happens is one part of the country at local clubs things are accepted then shooters come together at major matches and there is a dispute.
Thing to remember is equipment disputes are settled by a jury of shooters appointed by the match director, our club my guess is a 7/30 that's not factory chambered shooting low scores would go unremarked. Win a class it would likely be protested and the jury would not allow the rifle. If the rifle is at a local match where it's accepted not much risk. Take it to a major competition pretty sure to be questioned, then it’s in the hands of the jury.
Matches are won with ordinary rifles well handled. My opinion is best to use something that’s well within the rule and focus on breaking good shots.
Boats