How to clean the inside of the bolt carrier? How to you get that caked on carbon from that hard to reach area?
There are a few different ways to clean an AR15 bolt carrier group (BCG). One is to use a commercial solvent or degreaser, such as Gun Scrubber. Another is to use mineral spirits or brake cleaner. And finally, some people use a 50-50 mix of vinegar and water.
No matter which method you choose, be sure to start by scraping off all the built-up carbon deposits and other gunk with a brush or cleaning rod. Then apply your chosen solvent and let it soak in for a minute or two. Finally, scrub the BCG with a brush and rinse it off with warm water. Be sure to let it dry completely before reassembling your AR15.