Originally Posted by myfriendis410
I thought nickel cases were plated electroless. (Maybe determine that by sectioning--electroplate would be at least .001" and electroless about 1/10th that) That ought to reduce hydrogen embrittlement to some extent, especially if the brass is austenitized (sp?).
I've come across some shellholders that have a taller dimension above the base, which would reduce the die's ability to set the shoulder back (with some dies). The nickel plated stuff would be a bit "springier" and could revert partially back like Bindernut suggested. You might measure a few fired cases for overall length in both nickel and brass, then resize and remeasure. If the nickel "grows" less than the brass, that might point to your problem. Just a thought.
Yup, Remington's nickeled brass is electroless nickel.
The plating process isn't the culprit behind hydrogen embrittlement, it's the acid etch pretreat used before plating and also if the plating solution is a phosphite based mixture. All materials are etched before plating so even EN plated stuff may experience hydrogen embrittlement. There are lots of factors involved...a lot of which I don't fully understand myself since I'm just a hobbyist metalworker and not a materials engineer.
I have better luck with Remington's plated brass than the Winchester plated stuff (which is pretty scarce anyway).
Normally, I prefer to use regular brass for rifle cartridges, but in the case of my two .25-06s I keep those in nickel due to an ammo mixup that my dad and his .270 had a few years back shortly after I got my first .25-06.
You will probably have better luck and longer case life with unplated brass so I'd just deal with this lot until they're worn out and then replace with unplated.
Besides, if you do anneal your brass it's easier to see the color temp of the metal if it's not plated. Annealed nickel looks ugly too!