shoulder that is 0.400" in diameter
I just got off the phone with a Hornady tech, and he said for cartridges not on the chart (like the 6.5CM) to take the shoulder diameter plus the neck diameter and divide by 2 to find the diameter of the midpoint of the shoulder, and that'd be close enough. In this case it works out that the C/.375 bushing would be closest.
Interesting. I wonder why Hornady prefers .375"?
Which bushing should I use for 6.5 Creedmoor ?
Interesting. I wonder why Hornady prefers .375"?
https://www.hornady.com/reloading/p...gauges/headspace-comparator-anvil-base-kit#!/
If you're measuring from cases fired in your chamber and you want to set up your sizing die to move the shoulder back a given amount, either one will work. You don't need to match the datum-to-base dimension on a drawing, you just need to know when your sizing die's set to move the shoulder back as far as you want to, measured with whatever bushing you choose... 0.375", 0.400", 0.420" are all 'close enough'.
Nailed it!
Someone needs to explain to the OP if the datum/round hole is not the correct diameter the tool is turned into a comparator meaning the reloader must measure before and again after. If the reloader is measuring before firing and again after firing he is measuring the effect the chamber had on the case when fired. If he is measuring before sizing and again after sizing he is determining the length of the chamber from the datum/shoulder to the bolt face and sizing the case for clearance.
Many reloaders claim they move the shoulder back, at the same time they claim they are bumping the shoulder back and I ask; "How is that possible?" I can not move the shoulder back with a die that has full body support, if anything my shoulder does not move. I am able to shorten the case the case from the shoulder to the case head but if I managed that by moving the shoulder back the case would be 'rurant'.
And my cases do not have head space.
F. Guffey
Calibrate your case headspace gauge with a chamber GO gauge then zero the case headspace measuring gauge. Then note the difference on your cases. Add or subtract the number relative to the GO gauge.
Print them on label paper, cut 'em out then stick 'em on lock rings.
AGAIN, SAAMI SAID THEY DO.You of all people, Bart B. you called SAAMI, SAANI said the case does not have head space,
It's a scale graduated in .002" for practical purposes, within 16 millionths of an inch, to change die position.Again, Bart B. the little degree wheel is not necessary, it never was.
AGAIN, SAAMI SAID THEY DO.
Just like rimless bottleneck headspace gauges and chambers. They're well aware that the reloading industry and their customers agree that cases can have headspace. It's the distance from their back end to some point on their shoulder. There are several terms and conventions used in ammunition, SAAMI doesn't list all of them in their glossary.
Again, Bart B. the little degree wheel is not necessary, it never was.
It's a scale graduated in .002" for practical purposes, within 16 millionths of an inch.
Hornady has deviated from SAAMI standards before.Interesting. I wonder why Hornady prefers .375"?
Yes.Again, a reloader has only to verify and now you are telling me you make the adjustment without verifying?