One of the simplest ways to improve your shotgun’s performance is to change a standard MIM (Metal injection molded) extractor with non-MIM (solid steel) extractor. Steel extractors are used on the Remington 870 Police shotguns because they are more durable and allow heavy use of a shotgun.
An extractor is a part found in most firearms. It removes the spent cases from the ammunition that gets fired after you pull the trigger. With Remington 870/1100 extractors, you can use a non-MIM or a MIM extractor for the shotgun. MIM stands for metal injection molding. Newer Remington 870/1100 shotguns use MIM extractor. But the good news is that you can replace the MIM extractor with a Non-MIM extractor.