The KM gun disarms I've seen are suicidal. The best firearms disarms I've seen are in Kill or Get Killed by Rex Applegate.
How are they suicidal? I could see getting muzzle burns from them, maybe being grazed, but the idea is misdirecting the barrel away from you (keeping it in that direction) and pinning the weapon against a body. Usually involves someone's finger being broken in the take-away process as well.
Who the heck is Rex Applegate?
"Bow to your sensei!"