Q for those more expert than myself

[223AI]

If you're using dies that rely on the neck meeting the die (lee combine crimp and seat die for example) then I can see how this would happen. I much prefer the dead length seater die as the shell holder meeting the base of the die is a definite stop and leads to more uniform loads.

I would trim them all to the same length and load but do a couple of pressure loads at .5 / .2 gr under as you'll be eating up case capacity. Have they shrunk through fire forming?

[harry mac]

Did you re-size the empty cases before measuring them?

[angrybear]

If you're using dies that rely on the neck meeting the die (lee combine crimp and seat die for example) then I can see how this would happen. I much prefer the dead length seater die as the shell holder meeting the base of the die is a definite stop and leads to more uniform loads.

I would trim them all to the same length and load but do a couple of pressure loads at .5 / .2 gr under as you'll be eating up case capacity. Have they shrunk through fire forming?

I suspect so.

Did you re-size the empty cases before measuring them?

Yes, neck sized, RCBS if it matters

[223AI]

Trim to uniform length and load in that case, RCBS seater works on the case mouth as the datum, if they're only 5 - 7 thou short then pressure shouldn't be an issue unless you're at max load.

[harry mac]

I suspect so.



Yes, neck sized, RCBS if it matters

It does matter. When a case is fired, it swells out to fill the chamber, this often has the side effect of shortening the case. If you only neck size, you won't squeeze enough of the case back into shape to make it "grow" again.
measure all the cases and trim them all to the shortest length. At least then, you'll start with uniform case length.
A few thou short of minimum is no bother. They will grow eventually, but neck sizing minimises movement of the brass.

[angrybear]

It does matter. When a case is fired, it swells out to fill the chamber, this often has the side effect of shortening the case. If you only neck size, you won't squeeze enough of the case back into shape to make it "grow" again.
measure all the cases and trim them all to the shortest length. At least then, you'll start with uniform case length.
A few thou short of minimum is no bother. They will grow eventually, but neck sizing minimises movement of the brass.

Cheers, AFAIK they only make neck sizing dies for the K Hornet .

Another point I overlooked is that all these cases had also just been annealed, so I'll check again after fireing.