Hey Gents, it has been a long time since I have been on the forum but I have recently acquired a 4516 S&W that had some scratches on the slide. I removed them with a 80 grit bead blaster but it is now darker than the frame. I then lightly buffed it and it is much better but still fingerprints which the lower frame does not. So, I feel a bit embarrassed but need to ask if anyone here has done a nice bead finish on one of the old stainless pistols and how they got the finish close to factory. BTW the blaster at work most likely was not clean enough and more than likely had some additional abrasive in it causing at least part of the issue. Suggestions and pics are appreciated.

A bead blaster will impart the color of the media to the part that is blasted. For example, white silica sand gives the brightest finish, reddish brown flint will give a brown tinted finish, black silicon carbide leaves a blackish tint, etc.

To keep from fingerprinting, wipe down with oily cloth, then a clean one.

The easy solution in this case might be to finish the frame the same as the slide.

I was thinking the same thing but wanted to just try the slide first.

If I was doing it, I would get to a bead blaster that has 'fresh' media (of your choice, but I would likely use a mid range glass bead). I suggest unused media because when used it can pick up contaminants from previous jobs. If an earlier job was steel, you will have a bit of that mixed in and it can/will cause unwanted light rust, etc. Then I'd do both parts to get a good match. Go lightly.

So what grit size do you suggest? I tried 80 but with (like you said) the debris from previous jobs and an unclean cabinet, it was not the right smoothness.

The amount of air pressure you blast with has an effect on the roughness of the finish too. For example, light pressure (30 - 40 psi) will give a finer finish with coarse grit than heavy pressure (80 - 90 psi).

To match the factory finish I only use 270 grit beads from Brownells. I have been using these for over 20 years with a lot of happy customers. You will not get closer with any other grit.