22/250 Encore

[KN]

I have an Encore in 22/250 that is eating brass after three firings. Case head separations. After the third firing i can plainly see the crack forming just in front of the web. My load is near max with IMR 4895 and a 55gr Blitz King. I thought it might be a head space problem so I measured a loaded round (with extractor removed) and it measured .003" below flush to the end of the barrel. Add .002" for the barrel to frame gap and I have .005" head space. Does any one think that is excessive? Personally I didn't think it was. The only other explanation I can figure is a loose chamber. A fired round measures .003 larger than a re-loded round at the base. That doesn't seem excessive to me. Any thoughts or comments would be appreciated.   KN

[Grumulkin]

Try sizing the cases only enough to chamber and not any more.  The action should close easily but snugly.  You may be pushing the shoulder back excessively when you resize.  Better yet, just neck size and see if that helps.