There's one more indication that the problem is press flex and a need to screw the sizer down a bit more to compensate. Different makes (and lots) of brass have different mass and temper. It appears your Remington cases are somewhat more resistant to sizing than your LC. As a result, the press and sizer are probably flexing more with the stiffer cases and not receiving the same degree of reduction in head/shoulder length.

Before you decide to scrap those cases, try sizing them again after screwing the die down about 1/8 turn (.009") beyond where you had it set before. Then see how they chamber. You might be pleasantly surprised.