There's nothing extraordinary about the weapon, except that it uses electricity as its main power supply, which will runout in an incredible short period of time, which could mean that the main battery is half broken. Besides that, the chainsaw seems to be from a Warehouse called "WildTM".
It's a very powerful melee weapon but it's also very slow. Its use as a weapon is very limited; while the electricity to power it can be sourced from any electrical panel, it is very heavy and cumbersome to wield and since it consumes very quickly is not best to use it comfortably against common enemies. Though, to clarify, it's, as stated before, a powerful weapon which can kill enemies in 2 or 3 swipes.
Rather, it is used primarily for the purpose it was built for: as a tool, to cut through fallen trees and other large obstacles that block the path.
During the fight against Jedidiah and his ill father, this weapon will be instrumental as the chainsaw is used to cut off Leonard's vines while he and Jedidiah are recovering. At the end of the fight, Corey taunts Jedidiah about his now dead father, which makes him go berserk leading into a final chainsaw clash, which Corey, in struggle, won killing him in revenge of Sven, Mei and Jun,
During the whole game, the son of Leonard Friedman and Elisabeth Wickson, Jedidiah Friedman wields his own Chainsaw, which is different from the usable chainsaw, as itself is bigger, the "teeth" seems to be sharper and bigger, guide bar is larger and it's also covered in blood, propably from the other victims of Jedidiah. Huge difference is that this one use gasoline as its primary fuel and it has labeled a "RYAN" at the side of the handle and "RYAN GORH Chainsaws" in the metal guide bar.
The chainsaw is the most powerful melee weapon of the spin-off, you can find it in the last chapter "Green Thumb", near one of the roots to eliminate the upper floors of the high school. This weapon inflicts devastating damage to all enemies, and if you unlock the ability "Shots Loaded" the chainsaw will not only hit the enemy only once but the character will plant him continuing until the stroke charging ends. Thanks to this ability all the enemies that attack frontally will be swept away by the chainsaw.