I cant see how that would occur either Richard. I am unfamiliar with the trimmer in question, but usually they have a mandrel that holds the case neck central to the cutters (unless its a simple cone cutter).
I normally trim last, after neck sizing has been done, because it fits the mandrel properly and acts as a last check for splits I may have missed.
You would have to present the cutting blades at quite an angle to have it visible, but what I dont get is what Datum was used as the like I say, most rifle cases are slighly tapered to aid feed/extraction. You would need to use a surface plate and some sort of fixed datum to check it.
I'm a maggot in another life you know
I've trimmed hundreds of cases with one of these and have not had a problem, it's a really neat system.
The case is held in a shell holder in the press in the usual way, so should be presented to the rotary cutter correctly each time and a few turns of the handle soon trim off any excess.
Not camp, Gary just wishes I were!
Same all round the case mouth. This is obviously not the case for you but I really can't work out why.
Very odd!
Not camp, Gary just wishes I were!
I have one of these and is really handy tool very confused how it could go out of square. But what I'd do is trim then mark case with pen and rotate 90degress and see what happens because in theory if out of square it would then trim the other side
sorted