I just found a box in the garage with 50 pounds of ammo, shot shells, rimfire, old black powder and stuff not used in 50 years including some lead nose hollow point 357 mag. The lead shows corrosion and it feels sandy to the touch. Can I take some emery cloth and try and clean them up or it there a better way ? Any suggestions are appreciated.

I would start with something less abrasive, such as wiping the bullets with a piece of rough cloth like canvas. As long as the bullets aren’t contaminated with dirt or other grit, they wouldn’t have to be pristine pretty.

I don’t know what gun you plan to shoot them in, and it probably doesn’t matter, but I would not be surprised if they leaded the bore pretty badly. When I bought a Ruger 357 Magnum revolver some 50+ years ago along with a box of similar ammo, I couldn’t figure out why the accuracy was horrible after about 20-30 rounds. When I checked the bore, I couldn’t see the rifling due to leading. And getting it cleaned out was an … experience.

Added: In rereading your post, perhaps I misunderstood. If they are semijacketed hollow points, then there is obviously no reason to worry about leading the bore.

I was worrying about leading the bore and they are semi-jacketed. But what about a little "Flitz" or similar in the canvas to offer a little more grit but cleaner ? I bought the cartridges when I bought my Security Six way long time ago, the casing looks great BTW.

If they are semijacketed, the lead should not touch the bore and cause problems.
I don’t know if Flitz or something similar might help. It’s a pretty fine abrasive, so I couldn’t predict.

One thing I caution about using metal polishes around ammunition is to avoid using them on the cases—at least based on one experience I had. Long ago shortly after getting my first 44 Magnum revolver I thought it would be cool to polish the ammo to a nice bright finish. For whatever reason, those cases were extremely difficult to eject from the cylinder after firing.

Thanks for the replies sigfreund, I'll just try and rub off the surface corrosion.

I'd just rub them a little cleaner with a clean cloth, if you want. They'll probably be fine as they are.

I think I'll just do that. The grit is what worries me. Thanks for the help.