Ammonia is also very bad news on Steel alloys either in concert with certain other solvents and or if left in the bore for too long,uglydog said:I haven't used it but suspect it is much the same as automotive carb and choke cleaner which is a less expensive version of Gun Scrubber. As long as the ingredients don't include ammonia I wouldn't worry about using it. Ammonia reacts very poorly with aluminium causing it to spall. Ammonia is also noted to remove bluing, some types more so than others. I do run an oiled cloth over the gun after using any type of cleaner as they do remove the natural oils off metal surfaces. After letting it sit for several minutes I'll gently and quickly rub the gun down to remove excess oil. I haven't had a rust problem I could attribute to doing this yet.