OK. I've always, thirty years used a Forster. So the case is locked, as it were, by the collet gripping the outside of the rim, but it registers off the very bottom of the rim.

Now I've acquired in a job lot at auction a Lyman Accutrimmer. The case is locked by a screw into its base. Either with spent primer or into the primer pocket area. But it uses a shellholder. So the case registers off the front edge of the rim.

So. Here's the question. Which is less subject to varying trim lengths where in a series of cases the rim thickness and rim width are variable? Is the Forstér better, same as, worse than the Lyman?

Is the place where the case registérs better on the Forster collet type than the Lyman shellholder type. I know all about the Forster accessories...but rule them out of this discussion..which register system is better?

Or to me as a hunter not a benchrester or 1000 yard shooter is it any real world difference? I'm asking as I may be tempted to sell the Forster (I have the three base lengths plus three collets and five, six pilots) if the Lyman is effectively just as good.

And, of course, as I already have shell holder Lyman #2 and Lyman #7 all my calibres are covered now. Now all I shoot is .270; .280; 7x64; .30-06; .44 Magnum...and possibly .300 H & H Magnum. But no longer anything else in calibres.

Thanks for reading. Look forward to your answers.

You may be overthinking this. I have both. They do the same job, not one better or worse. Trim then measure.

Thank you for the input. Your side-by-side experience is valuable to me. Thank you.

It doesn't matter how the case is held as long as the pilot, collet and case are square to the cutter.
I use the lyman and insert a case held lightly by the collet until the pilot is inside the case mouth the lock it