According to my calipers, the Q5 uses an unusually thick fiber rod in front: 1.7mm. But commonly found replacement rods only go up to 1.5 mm. Most are thinner, in fact. Could it be that I'm measuring it incorrectly? Seems like other guns I have with fiber optic have 1.5 mm rods. So, is there a source of 1.7 mm replacements, or should I just put a 1.5 mm rod in and let it rattle a little?