Sticker removal tips.
1. Pull the sticker off very slowly. In many cases the adhesive will stick to the sticker and not to the gun. If you pull the sticker off fast, you increase the chances of leaving adhesive, you will tend to leave more adhesive, and you run the risk of tearing the sticker. Tearing the sticker is a pain because for the rest of these options to work, you will need to remove all of the label part of the sticker first.
2. If there is adhesive left on the gun, you can use duct tape to pull the adhesive off the gun without using solvents or scraping. Stick the tape on over the adhesive and pull it off. The tape is stickier than the gun and this will usually remove the adhesive. You may need to do this repeatedly (you can usually keep using the same piece of tape) until all the adhesive is removed. For this to work, the label part of the sticker (tape or plastic) needs to have been removed.
3. If you are left with some really sticky mess that won't come off using the tape method, vegetable oil will often work. Just put some on a paper towel (if you have a really high polish finish, maybe use an old CLEAN cotton rag instead as some paper towels can be slightly abrasive) and the rub away the adhesive. Most CLPs will work even better, but the vegetable oil is good for plastics or wood that you may not want to use an aggressive solvent on. Ballistol is a good option that isn't hard on most wood finishes.
4. If you still have something that won't come off, you can try Goo Gone--it almost always works.
5. A white plastic eraser (NOT THE ABRASIVE pink or white erasers) will often pick up little bits of rubbery adhesive that are stubbornly sticking to a surface.
6. Brake cleaner/pneumatic tool cleaner is the final option and I've never had it fail. I usually go up through the steps rather than just start with this because I don't like the smell and because it has the potential to ruin things more than any of the other options.
If the sticker won't come off, you can use a piece of wood or plastic to scrape it off. If it is a paper sticker you can put something like Goo Gone on the sticker to soften it first. If it's a plastic sticker, just get to work.
If the adhesive has dried really hard--I've seen this happen with really old stickers that have been left in place a long time, you can try a solvent on it, but you're probably going to have to scrape it off with a piece of wood or plastic.
Goo Gone or what I think is it's principal ingredient, acetone.
Goo Gone is a petroleum based solvent with a smell added.
