Threat is a modern micro armor game. The authors write:

THREAT is a modern-era miniatures wargaming ruleset that was designed to be a fast-moving fluid game of modern tactical ground combat using 1/285 scale miniatures.

THREAT is a very realistic simulation of the deadly modern battlefield. Combat is simultaneous, for this reason a referee is recommended to direct resolution of the firing and resolve line of sight (LOS) problems. Each miniature represents a one-for-one ratio of personnel and equipment. Aircraft may represent multiples of aircraft of similar type.

Unlike other game rules, THREAT does not use individual vehicle charts, rather it uses charts for each weapon system that modern vehicles employ. In this way any number of vehicles with different weapons mountings can be utilizied without having to create new charts.

Micro Armor Devastation

Micro Armor Devastation is a set of fast play miniatures rules for land and air combat from World War II onward. They’re very nicely done in a pdf format.

Airland War Rules

Airland War is the successor to Steve Lorenz’ successful, commercially published Panzer War miniatures wargames rules. The rules simulate modern warfare using microarmor miniatures. You can now get Airland War as a free download.

Panzer War rules

In 1979, Steve Lorenz published Panzer War, a set of miniature wargaming rules for World War II microarmor. It was moderately successful, and in 1981, the second edition, Panzer War II was published. Having long since sold out, Steve has elected to offer these successful wargames rules free as a download.

Steve describes his set:

Panzer War is a set of war game rules simulating World War II armor warfare that will eventually use a variety of scaled miniatures. Currently it is scaled for 1/285 scaled models. Each player can assume the command of a platoon or company of troops. Panzer War includes rules covering weapons, vehicles and troops used during the conflict from 1938 through 1945. Warfare on and over the battlefield is simulated in a detailed and realistic manner. The scale being one vehicle model for one real vehicle and one infantry stand per infantry squad. The game may seem complicated at first once the basic rules are understood and experience is gained they will become second nature to the players. After familiarizing themselves with the basic rules players should move on to more advanced rules one step at a time.
And yes, there are a lot of charts and tables.

Shellshock Combat System

The Shellshock Combat System is a comprehensive set of free wargames rules for WWII, Modern and Science Fiction combat. Designed for micro scale (1/285), it features three “levels of play”: basic, advanced and “blitzkrieg” (fast play).