Thread: Case lengthening when bump sizing

Originally Posted by Micky Duck

Attachment 217894

Thanks for posting that , though personally I'm not convinced that depiction is completely accurate as the case goes from no contact to perfect fit in one step . The books are on occasion wrong , for example in one of the Hornady manuals, they show the datum point to be at the base of the neck as apposed to it being mid shoulder. If your a bit mean with the lube , cases will often bare witness marks where it has started engaging the die way before the neck would even have start to be sized . Again, just my opinion based on my experiences .

So before this goes a lot further, please don't let this become an argument, my post is to encourage debate and discussion .

I have witnessed the case lengthening , measured at the shoulder using a comparator . So nobody will convince me I'm wrong on that account it can and does happen and has caused an few others some issues . The explanation I've given is the opinions of others as well as my own . The cause is really the point for discussion .

I've said this before , "I never mind being proven wrong in fact I'm used to it , I'm married! " But , so far nobody has put forward a compelling counter theory to convince me that I am wrong in my belief of the cause .