Get some Klein side cutters, blue handled.
They are designed for electricians...the blue ones will cut 3" Ardox nails with no problems.
I've used the same pair for the last 6 years in the trade...
The red handled ones are meant for soft metals only.
Depot sells them, last time I checked they were around $30
Also they have a lifetime warranty, so if the cutting edge somehow chips, they'll replace them over the counter.
They don't, however, replace them if you blow a hole through them by cutting live wires
