(click on the photo to enlarge)
There is some question about nickel cases and premature cracking from multiple reloading. Does it happen? A resounding.... Yes. Is it a real problem? Maybe.
The .45acp cases pictured above are of several brands, and all were found to be cracked during examination while reloading. They are in a batch of roughly 500 well used casings of about the same vintage, and have all seen roughly the same loadings.
While the nickel cases in this batch are showing cracking about five times as often as the plain brass cases, it might be worth noting the wear on the cases. This brass has been reloaded in excess of twenty times..... and owes the shooter nothing. As can be seen, it's been through the process so many times the nickel plating is actually wearing off the cases.
I take away two points from this situation:
- I will not hesitate to reload nickel cases when I have them, and have no fears of 'short' case life with nickel.
- I will examine nickel cases a little closer during reloading, and reserve them for mild target loads where a missed crack may not be such an issue.
Nickel plated bottle neck rifle ammunition is another story, and can cause reloaders to have fits. The hard nickel coating resists sizing to a point, and the higher pressures involved promote cracking at a much higher rate. They can also be a pain to trim, and are hard on the tool heads.
That said, nickel plated rifle cases are a fair choice for hunting, as they feed very smoothly and won't corrode under even the nastiest conditions. They'll have a shorter reload life than brass cases, depending on reloading method and pressure of the loads, but five or six loadings out of a single rifle cases are still possible.
For nickel plate pistol brass... the photo above speaks to that. Yes, nickel cases will crack more often, but not enough to shy away from using them. All it takes is a little more close examination as they age.
Commenter Sigivald asks a good question, and one I should have thought of myself. Exactly why do nickel plated cases tend to crack more often?
I think it has to do with the nature of nickel and brass, and their being dissimilar metals. They expand and contract at different rates, and react to sizing in different ways. One metal is trying to expand .005", while the other is attempting to go .008". The stress and strain put in place can pull metal apart.
I have read that the internal stresses inherent in the nickel plating itself leaves it stressed at 50% of it's fracture point even while sitting at rest. Add in repeated firing expansions, pressure, resizing, expanding, and crimping.... and something is going to happen. Brass is much more forgiving.
After photographing some nickel plated cases showing flaws (example above) I noticed that some cases have cracks in only the nickel plating... and not the underlying brass. This would imply flaws in the plating process, and delamination of the metals. I have to think such a crack in the plating would quickly lead to a case cracked completely through the body.