The Problem Of The Needles,
When I ordered my mini barreler, I also bought 750 g. of mixed shot from Sutton tools, Which seemed the cheapest option at the time. It arrived in three separate bags and keen to begin, I blithely mixed them together.
As mentioned by other members in the past, my test pieces, tumbled for about two hours, came out covered in tiny but quite deep pin marks. This was less so on round and sloping surfaces, but very pronounced on the flat parts.
In the interests of research I then picked out all the needles, which were the obvious culprits. They were quite roughly cut with sharp points and burred edges. Tumbling them with pebbles for hours and hours did reduce the burrs, but still left sharp points, so finally I ground each end with a mounted stone on my flex-shaft until I had 75g done.
Adding these treated needles to 400g of mixed balls and satellites, gave a much reduced proportion of needles ( Approx.16% instead of the previous 33%) And left a lighter texture, which was more easily removed with radial wheels or micro mesh.
Trimming the needles and/or reducing their proportion will give a more superficial texture, which is not unattractive and can more easily be removed from selected parts of your work.
Alternatively, as suggested by Leslie, keep a separate cache of shot, free of needles when a smoother effect is needed.
Sorting Shot On A Tea Tray
The Pin Point Texture
The offending Needles
Final Texture And Texture Removed.