On the quick reference card artillery melee is annotated "sabers hit". Does this mean that only sabres count as hits? I can see nothing in the rules sbout it, but can see no other purpose in the comment on the card.
Can you specify this, there are a lot of reference cards (nations). Official and unofficial. So your question is only 30% complete, to answer it
You should always refer to a source, where you saw/read it, either a link (if it´s a download file) or an attached picture (if it´s a physical reference chart).
Only thus make a right answer possible, if there is any mistake in any reference chart/card or you simple missread/missunderstand something
As a general rule, sabers do count as hits when artillery units are engaged in melee (along with INF, CAV, and ART dice results, as appropriate). As an example: an artillery unit is in melee against an INF unit, and it rolls 4 dice. The results are saber, flag, INF, CAV. The opposing infantry would take two hits, 1 for the INF and 1 for the saber. It would also have to retreat 1 hex, subject normal limitations like Grenadier units, attached leaders, etc. Basically, artillery in melee acts like any other non-militia unit in melee, with the exception noted below.
The exception to the above is when artillery units support militia units in a combined arms attack. In that case the sabers do not count as hits.