It's not unusual for cast bullets to have a 3-grain weight span, especially coming out of multiple-cavity molds. It's just not enough to upset normal pistol range accuracy with them. In the case of 184 vs 200 grains, that's a much bigger difference and would affect point of impact in a revolver, impacting lower. I suspect, as already suggested, they were in a mislabeled box.
That said, other than a sight adjustment, it won't impact normal revolver shooting much. Even a SWC, which has more drag than you will with a round nose flat point, if I load the two weights to the same muzzle energy, running the 200 at 900 fps and the 184 at 938 fps and adjusting the 200 BC of 0.194 down to 0.1785 for the lighter bullet, zeroing both at 50 yards and assuming a front sight post 0.7" above the bore axis, the peak of the trajectory for the 200 is 1.1" at 28 yards and the peak for the 184 is 1.0": at 29 yards. The difference in total bullet drop (what you would see if you fired horizontally rather than with zeroed sights) is 5.5" and 5.1" for the heavy and light weights, respectively. If you are seeing 0.4" difference clearly at 50 yards, you are shooting better than I am. The difference in drop doesn't reach 2" until 140 yards, by which time you are well out of any sight adjustment range you are likely to have.
