Originally Posted by
Lunkerdog
... The first issue that came up was case stretch in front of the head. The guy that was teaching me was trying to do a "partial" resize, and the shoulder wasn't getting set back. This quickly developed into a pressure issue that we would more than likely not have been detected right of way had we not been using his Chrony.
I can see the same type of issue happening with the .300 if the cases aren't being fully resized properly...
Not to hijack this thread, but you've got me puzzled here.
First, I successfully reloaded .30-06, .308 Win, .30 Gibbs, .257 Ackley Improved, .22-250, and a few others for about 20 years before I bought my first chronograph. Now I'm also reloading .375 RUM, .300 Weatherby, and 7mm Rem mag, and I've also upgraded my Chrony which I do use for all load development.
For at least 30 years, I've also "partial" resized all of my reloaded rifle cases by placing a 0.030" washer under my FL sizer die. This included all of the ammo that I took and used on a half dozen international hunts. Many bench rest competition shooters only neck size their cases. Either of these procedures insure that the resizing
does not set the shoulder back, and that the cartridge will perfectly headspace on the shoulder of the case, which enhances accuracy and minimizes stretch of the body of the cases..
My next reloading purchase will be for Collet Neck Sizer dies for the cartridges that I shoot the most, including my .300 Weatherby.
Ok, so my questions are, how does partial resizing develop a pressure issue?, and how would that pressure issue be detected with a chronograph?