My experience with nickel plated brass is that is much more prone to splitting than bare brass. For this reason, I avoid it.
I have noticed this mostly in the 38 special ( loaded with 148 gr HBWC and 2.8 gr of Bullseye) By no means a damaging load.
I have also noticed it in my 44 mag. I don't have any plated rifle brass.
I am not sure of the reason. Possibly hydrogen embrittlement if it was electroplated. Electroless plating should avoid this problem.
The other potential cause of splitting is ammonia in the cleaning or tumbling of brass. Brass is subject to intergranular corrosion, and subsequent cracking in the presence of ammonia.
If you are really set on nickel plated, check to see if there is a plater in your area who does electroless nickel plating. Ask him how much to plate the brass. Use a plating thichness of .00005in when requesting a quote. The will charge you based on surface area and number of pieces. It's best to do it all at once, as setup charges will affect the cost.