So I found myself in a little bit of a conundrum today at the range. I have a nasty habit of stock piling brass as I find it at a good price. I've never seen this happen before in over 20 years of reloading. I had a bag of brass that had 10 new ones that I had bought back in 2008.
I rounded out my range box with the contents of a bag that I had purchased last month when I found the brass on sale again. Cases from both bags were reloaded with the same charge of Winchester 760, a standard large rifle primer and the same 117 grain Hornady projectile. The charge used was over a grain below the maximum listed in the latest Hornady manual. This is a load recipe that I have used in the past with no issues. Today it was a bit different.
There was no noticeable change in recoil, or shift in point of impact while firing the rounds. I was in the process of zeroing in a new scope, and as such I was more concerned with getting my scope zero than with inspecting the casings (not a new load) had I been working up a new loading.
When I was policing my brass, I noticed that some of the cases were rather dirty compared to the others. Upon further inspection all the cases from the old partial bag had multiple splits in the shoulder area of the case. All the cases from the new bag were perfectly fine. None of the primers or case heads showed any of the tell tale signs of excessive pressure.
I'm scratching my head about why this happened. The only thing I can think is the culprit is bad quality control over the annealing process. I pulled several of the projectiles and weighed the powder charges on one electronic and one balance beam scale and the powder charges are completely as expected. The only answer I can think of is that there is something wrong with the annealing on these cases from the manufacturer.
A common sense check would be appreciated. I've attached some pictures.
I rounded out my range box with the contents of a bag that I had purchased last month when I found the brass on sale again. Cases from both bags were reloaded with the same charge of Winchester 760, a standard large rifle primer and the same 117 grain Hornady projectile. The charge used was over a grain below the maximum listed in the latest Hornady manual. This is a load recipe that I have used in the past with no issues. Today it was a bit different.
There was no noticeable change in recoil, or shift in point of impact while firing the rounds. I was in the process of zeroing in a new scope, and as such I was more concerned with getting my scope zero than with inspecting the casings (not a new load) had I been working up a new loading.
When I was policing my brass, I noticed that some of the cases were rather dirty compared to the others. Upon further inspection all the cases from the old partial bag had multiple splits in the shoulder area of the case. All the cases from the new bag were perfectly fine. None of the primers or case heads showed any of the tell tale signs of excessive pressure.
I'm scratching my head about why this happened. The only thing I can think is the culprit is bad quality control over the annealing process. I pulled several of the projectiles and weighed the powder charges on one electronic and one balance beam scale and the powder charges are completely as expected. The only answer I can think of is that there is something wrong with the annealing on these cases from the manufacturer.
A common sense check would be appreciated. I've attached some pictures.
