Give Me a High 4, Jose

There are a number of rules to responsible gun ownership.

Number 1 on the list should be, "Make sure that the gun is unloaded before you try to clean it."

It appears that this bit of common sense has escaped former Baseball all-star Jose Canseco:

Former major league slugger Jose Canseco blew his middle finger clear off his hand while cleaning his handgun at home in Las Vegas.

Jose's fiancée Leila Knight tells TMZ Sports ... he was sitting at a table in their home cleaning the gun when it went off. She says he didn't know it was loaded -- and the shot ripped through the middle finger on his left hand.

Leila tells us 50-year-old Canseco is in surgery right now as doctors desperately try to save what's left of the finger. She says the bullet tore through the bottom part of the finger and doctors have already said he'll never have full use of it again ... even under the best of circumstances.

Here is a suggestion for gun owners out there, and I am not kidding: create a checklist for yourself for each weapon that you own, much like the one that is used for flying aircraft.

If you use it, one of the early steps will be something along the lines of, "Remove the magazine and confirm that there are no rounds in the chamber."

Really, I am not being snarky here.

Everyone has a brain fart occasionally, and that is what check lists are for.