The way the die could be an issue is excess working of the brass. Standard dies have to work with the thinest neck walls made, so they over-resize the average neck wall too small and then expand it back out, overworking it going in and working it the other way coming out. Both steps add work hardening. If you go to a bushing die and select a bushing generous enough so your particular lot of brass is only resized to final size, you skip the over-reducing and you skip the expansion, reducing overall working of the brass. If, in fact, the neck portion of your chamber is generous, then this will compensate to some extent by reducing how much the brass is worked further for each reloading cycle.
RCBS makes both Full Length and Neck (only) bushing-type sizing dies. I have no reason to believe there is any problem with them. Just be sure you get the one you need. You should not have to buy it as part of a set with their Gold Medal seating die. I do not find that seating die design to work as well as the Redding and Forster competition/benchrest designs. And it at least one test by John Feamster, it was found not to work as well at minimizing runout as the standard RCBS seating die does.
But this begs the question, is your chamber oversized? You can tell by measuring your as-fired cases.