Matt accuracy is kind of a "relative" topic and depends on what your expectations are. If Lead or jacketed bullets will hit the A Zone out to 50 yards in your guns when you apply your skills then they are just as accurate as FMJ in the form of BDX which are Montana Gold bullets made in Calgary. If, you are shooting Bianchi Cup and X's count more than the 10 ring the FMJ might make a difference but from my experience my flyers, if you will are on me not the bullet. I have shot 3/4" groups at 100 yards with my GC Lead bullets out of my Husky 30-06 that are as good as I can shoot FMJ bullets and have similar experiences with all three bullet types off a rest in my pistols (at 20 yards) once the load is dialed in.
I guess what I am saying is given quality made bullets be they lead, plated or FMJ, the results for most are no different. Get the load right under your favourite pill and your misses are on you.
Take Care
Bob