.222 rem case

[wj kerr]

hello all have a question regarding case length am working up a load in .222 rem using h322 made 7 rounds at 21.6 grains 7 at 21.9 and 7 at 22.2 with rp new brass and cci 400 primers checked case length before reloading it was around 1.694 after i test fired all cases had shrunk to around 1.685 what is going on here. once again thanks in advance.wj.

 

[Walkalong]

Normal.

Cases swell to fill the chamber, becoming both wider and shorter. Size them and they will narrow and lengthen again.