Otis nylon gun brushes are handy to have around when it comes to gun cleaning. They are awesome for scrubbing bolts, inside receivers, trigger assemblies, gas pistons, Glock slides, magazine wells and magazines. They are effective at loosening dirt, fouling and debris without harming any part of a firearm. They really make gun cleaning easy and faster.
The only drawback to nylon brushes is they will not remove burned on carbon fouling like on the AK-47 gas piston. You have to use bronze brushes to remove this stubborn carbon buildup.
These are Otis Nylon brushes and they work great but you can get just about any name brand and they will work. Otis just happens to come in packs of 25 brushes.