My friend has a S&W 686, and there has never been a problem with split cases fired from that revolver. These are new unfired cartridges out of a new box. Ten of the fifty came already split. I don't know if it is worth the time and expense to send the box back to Remington. My suggestion was to return the box to the gun store and exchange it for another box, preferably a different brand. For 10 out of fifty to be split tells me that the cases were not annealed properly after forming, and if the store has any more boxes, they should inspect them for split cases also. I don't know what will happen if those cartridges are fired in a revolver, but I don't want to find out.
I have seen some weird stuff from Remington over the years, including a box labeled for .223 Remington but actually containing .17 Remington cartridges. After firing several cases of Winchester .223 cartridges, we found one cartridge with the bullet loaded backwards in the case, but one out of about 2000 is not bad. After firing many many boxes of Federal .357 Magnum cartridges, we found one with the primer loaded backwards. Again, one out of countless cartridges ain't bad.