Larry Medler came up with a clever little invention – a simple and inexpensive Empty Chamber Indicator designed for rimfire guns. It is made out of a plastic “weed-wacker line” and a wooden sphere from a hobby store. Larry says that Juniors used something similar to make their 17-Caliber Air Rifles. How to Make an Empty Chamber Detector: Drill a 7/64″ diameter hole through the wooden ball with a 1″ diameter. Use a 13/64″ drill to enlarge the hole by half. Insert an 8” piece (0.095′” diameter) of heavy duty weed wacker through the ball. Leave about 2” at the side with the larger-diameter. Fold the line over half an inch at the end, so that it is doubled. Slide the line into ball, stuffing doubled-over section in the 13/64″ (large) hole. Pull the longer end of line until the doubled over section is flush against the outside of ball. This method allows you to attach the line securely without using messy adhesives. Hold the ECI at the tail end and dip the ball into yellow paint. If you are making more than one ECI you can drill horizontally in a spare piece of wood to use as a drying rack. All shooters are required to have an Empty Chamber indicator at a Rimfire Sportster match. The Empty Chamber indicator for Smallbore Rifles
Larry explains that “Open Bore Indicators, or what is now called Empty Chamber Indicators, were mandatory at all Highpower Rifle matches, silhouette matches, as well as other shooting events. The NRA’s yellow ECI is easy to use, and well received by shooters. I had never seen an ECI that was truly functional for 22 rimfires until I visited Michigan’s Washtenaw Sportsman’s Club, where I saw juniors use ECIs for 17 Caliber Air Rifles. Someone at the club made empty chamber indicators using an 8” piece weed wacker to a 1″ diameter wooden ball painted bright yellow. I now make ECIs similar to the 22 rimfire matches I run.”