about 80 % of ejection and binding bolt problems can be traced to cleaning of the bolt or chamber .As far as the bolt is concerned Eric
on you tube gives a really good video of bolt disassemble and re assemble!There are all sorts of cleaners that you can use on a bolt to clean it , brake cleaner and carb cleaner and mineral spirits.Dont forget to oil the bolt!!
Moderator feel free to use the above as a sticky