I remember using it during my NS days for those heavy weapons like the GPMG. All the stubborn carbon and rust were easily removed with just one wipe.. LOL . .

Apart from cleaning M16 rifles, I used it often during my technician days as an NSF. This wonderful bottle won't disappoint me to crack open those stubborn rusted bolts and nuts that held those old L/Rs and 3-tons in one piece.

Ohh! My colt plus also has the same issue, when it closes it makes an irritating noise.. Later I go check it out, find the joint and spray some WD40 too!