I don't want to start a war here, but Brasso makes brass less elastic over time because of it's ammonia content. I used to use Brasso a lot, but quit when my case life dropped to only 1-2 reloadings. There are plenty of effective case polishes out there to choose from. Brasso is great for brass furniture & other things that don't expand & contract. I had 41 & 44 magnum cases splitting their entire length within a maximum of 2 reloadings.