I chamber my M14 rifles right in the 1.632 range. My brass case headspace is set at 1.628. After firing cases stretch approximately .006 to .008 or right in the 1.634 to 1.636 range. All lube is removed from cases after loading. Been doing it the same way for 46 years with no troubles. Mil brass,current load used 41.5 4895 CCI #34. 168 smk.