Cleaning brass

[Spaceinvader]

Hello all,
I recently got a decent condition 3"50. casing from a local military surplus shop. The problem being it looks like someone either got some acidic stuff on it, or tried cleaning it and gave up half way. Some of the casing looks normal, with its 20-ish years of patina, others parts look new and shiny. So im just wondering, whats the best way to clean brass? I know there is lots of threads on here but after reading them I either cant find the stuff here in Canada, or their is dispute on weather or not its good/should be used. Hopefully someone can give me a definitive answer. Thanks,
Rhys

 

[thekees]

I would clean the case completely and polish it afterwards. After polishing and getting a homogene brass case, you can choose to leave it that way or tone it down by aging the case.

 

[peregrinvs]

To strip it back to clean metal, I would give it a dip in dilute citric acid and then finish off with metal polish.

 

[tucco]

Vinegar, always save your vinegar you use, iv got about 10 gallons now, you can put a blue green brass rotten shell case in it for 10 / 15 minutes, a gentle rub down for 5 mins with a washing up nylon scrub, including the inside of the shell case, & its ready to polish, no dirty brass scares me at all these days,