Thread: A couple of new toys comp seating die and Comparator for Measuring sholder bump etc

Hi Rambo, I use the same two pieces of kit and I get the CBTO reading within .002" . The micrometer seater seems good but I'm moving in jumps of .005" at a time. M
Remeasurung the same case several times gives readings within .001". Measuring case base to bullets tip does vary a but up to .005" sometimes due to the plastic tips varying a bit I guess.

Looking at opportunities for improvement: try rememeasuring something several times like a case length . Should be the same each time to + or - 0.001" . If not theres a problem with your feel or the micrometer or dirt/ grit somewhere.
I gently rotate the case in the caliper when using either bullet ogive or shoulder gauges. It often settles in. Usually the case base isn't sitting completely flat and square on the caliper when I first put it in place.
I use a little red "anvil" attachment that the case base sits on on the caliper. Stupidly expensive for what it is.
A final problem I've had is with compressed powder loads where the press springs a little and the bullet isn't seated to the same depth as when there's less powder in the case and it's not obstructing the bullet being seated right in. This can be up to. 020" in my limited experience
could be a press problem out of line springy or something.
Some people size their brass then rotate it in the sizing die and resize. This is in case the base isn't square due to crooked chamber or perhaps die. That could give crazy different measurements each time you do it.
I use a forster coax press which has the die mobile so it can center itself on the case which some people say is better for concentricity and stuff.

I think they are both good pieces of equipment and highly recommend.