Sec. 227c.
(1) Except as otherwise permitted by law, a person shall not transport or possess in or upon a sailboat or a motor vehicle, aircraft, motorboat, or any other vehicle propelled by mechanical means, a firearm, other than a pistol, which is loaded.
The only problem with reading that is from the part that says a person "shall not transport or possess...a firearm, other than a pistol, which is loaded"
Reading it in the whole context it would seem to make anything firearm that is not a pistol illegal.
And I say that because contextually the phrase "other than" typically excludes the item immediately following, in this case the pistol. A term that can be and is used in place of "other than" is "except for." So it could also be read as except for a pistol, meaning the pistol would be exempt from the statute.