It's been over two years but I'm bringing this back to life for one of my own entries and hopefully some of ya'll will add more too...
As some of you know, I have recently converted a Savage 11 from it's original .270WSM to .243AI.
So, I'm in the process of working up my first "real" loads. I do all my measurements, set the starting charge and use QuickLoad to predict the max charge.
I load up all these rounds and, wanting to clean the residue in the barrel from a previous powder, I run a couple patches of cleaner, a dry patch to verify and then a patch with what I thought would be "lightly oiled".
I get to the range and notice on extracting the first shot that the case had a surprising amount of oil on it. Huh, but, no ill effects as far as I can tell...
As I get a step below max load though, suddenly MAJOR extractor impressions.
Obviously I stop the work up and even more closely examine the other cases. I notice that I can see faint (very faint) extractor marks on almost all the cases.
Obviously, something is wrong.
Well, long story short, I'm convinced that the oil was having some affect, by increasing bolt thrust but...
The entry to the Shelf of Shame, such as it is... I had intended the rounds to be .050 off
the rifling but somehow I had ended up 0.100 INTO
I guess the gun is good, anyway. QuickLoad thinks that load with the bullets jammed was around 71,000 PSI.