This picture shows the first sign of headspace separation on two fired
.308 Winchester cases. Notice the bright horizontal ring near the base of these cases. This is a common problem for shooters
that reload if they don't resize their
cases properly. Avoiding this symptom often means going beyond just reading the instructions that came with your reloading dies. Headspace
separation is caused when the case shoulder gets pushed back a few thousandths of an inch too far during the resizing operation. If you measure
your cases (at the shoulder), this can be avoided.
If you ever experience this warning sign of headspace separation take it seriously, and throw those cases away.
The next firing would definitely split these cases in two, leaving most of the case stuck in your chamber. The escaping gases can blow back
through the bolt, and cause serious injury.
If your headspace is a bit too long, your handloads might not chamber properly. If the case shoulder gets pushed back a bit too far,
your handloads will be too short for your chamber. When a short case is fired, its shoulder is blown forward until it fills up the chamber. This
stretches a case just above the web (the solid part of your case). At this point the case becomes paper thin, and it's wasted. These
cases could have been used for many more loadings if they had been measured during the reloading process.
Until now, hardloaders have used several different methods of measuring headspace. These methods include coating fired
cases with soot from a candle or using a Magic Marker and chambering it to see where it contacts the chamber. Well . . . . now there's a
much better way . . . .
