Painful, sore, red gums can be a symptom of gingivitis (inflammation of the gums) or, more likely, periodontitis (inflammation of the attachment fibers of the teeth and supporting bone), which can arise due to a number of different causes.
klick (plural klicks) ( 1 slang, military) A kilometer. 2002, Robert J. Sawyer, Hominids an asteroid between one and three kilometers wide had slammed into the ground at fifteen klicks per second. ( 2 slang, usually in the plural) Kilometres per hour.
It is preferred to either have both a MIL rerticle and MIL adjustment (MIL/MIL), or a MOA reticle and MOA adjusment (MOA/MOA) to utilize the strength of each system. Then the shooter can know exactly how many clicks to correct based on what he sees in the reticle.