I use nickel coated brass for various cartridges and have never had a problem. It often doesn't trim as nicely/cleanly and is sometimes a bit more stiff to size but that's about it. I've also noticed it gets brittle and splits faster like others mentioned. I use nickel brass for hunting rounds as they don't tarnish when sitting in a pocket on a cold, wet autumn day.
I thought I ruined a set of 308 dies once with nickel brass but it turned out to be sand or grit that got on the cases. I was using spray lube in an old box and the box wasn't clean. The grit scratched up the inside of the die and those scratches transferred onto every case sized after that. I since stopped using spray lubes (for various reasons, not just this one) and haven't had it happen again.
I say coated and not plated because not all manufacturers use an electro plating method for coating brass. Some use a proprietary chemical dipping process that is a company secret (I forget which brand does this).
No one told me, as I said, I read it.
It was either in Handloader Magazine or another publication, written by an experienced reloader.
The writer didn't sound confused to me.
There is a LOT of misinformation in popular reloading publications written by very experienced reloaders. Old wives tales and rumour get repeated over and over until it becomes factual in many peoples minds.
I have read in major reloading publications the following:
-if a bullet falls on the ground, throw it out, it may have been knocked out of tolerance and can blow up your gun and kill you
-if you let cast bullets touch each other, they're garbage as they'll be wild flyers when shot
-if you allow primers to touch each other, they'll explode and kill you
-oil from your skin can chemically deactivate primers
-tumbling loaded cartridges will break down the powder inside and they will detonate and kill you when fired
-loading black powder into cartridges will cause a detonation and kill you
-if even a drop of ammonia touches your brass, it will explode when fired and kill you
-removing live primers from cases will cause an explosion and kill you
-nickel plated brass needs carbide dies because nickel is much harder than tool steel so it will gouge your dies
-exceeding published load data by even 1% will cause a detonation and kill you
-going under a published starting/minimum load will cause a detonate and kill you
I could keep going.
All these statements are either flat out totally wrong, or wrong to varying degrees.
The modern, sarcastic saying "you read it on the internet, it must be true" also equally applies to books. There is no law stating that the information printed in books be factually correct.