I have Forster Benchrest seating dies in two different calibers.

For those that don't know them, these are similar to their competition dies in that they have a floating "chamber" that align the case with the bullet before the seating process starts, but they do not have the micrometer adjustment feature.

I have found that they give me reasonably good concentricity (although I suspect that has more to do with case quality and condition than die design) and excellent seating depth consistency, but they are rather difficult to set to the desired depth.

One can buy the micrometer heads but they are (by my standards) relatively expensive. And my experience is that once I have a load I tend not to fiddle with seating depth that much.

I did some measuring and found that the OD of the die body and the thread of the adjusting spindle of the two dies is the same. So I made a setup that bolts/clamps onto the existing die and gives me adjustment inciments of very nearly 0.0005" per click.

Once the die is set I can lock the spindle using the original lock nut and remove the adjuster mechanism.

Attachment 35489

Attachment 35490