Well CC Griff, you probably heard right. I may be thinking of some other movie for the rubber rifle. The Wikipedia page for the movie states:
"Three fully functional .45-110 rifles matching the above description were built for the film in 1989 by the Shiloh Rifle Co. of Big Timber, Montana, United States. They also had a 15 1⁄4 inch length of pull to fit Selleck's tall frame, a full octagon heavy barrel with a blue finish, and weighed 13 1⁄2 pounds. Due to the weight, one of the rifles was sent back to Shiloh to be refitted with an aluminum barrel so it could be swung faster (as a club) in fight scenes."