That doesn't sound like the dies fault, that sounds like a gun with a chamber smaller than SAMMI minimum.
I believe I said that, except that MY rifle chamber used as my example is at the SAMMI minimum according to my gun smith...evidently, that can cause problems. I personally think the problem lies in the fact that nothing is perfect. Dies, Chambers, Factory Ammo, certainly reloaded ammo...add that all together and things happen once in a while unless everybody stays in the center of the SAMMI Specs. Unfortunately they sometimes don't.
RCBS is into selling dies, and things like "AR dies" sells. I think it is excellent sales technique. Won't dispute that, but please, Dillon makes small base dies, and people say they're wonderful. RCBS makes them and its a gimmick. Double standard IMO.
They include a small base die to get less complaints from folks who are sloppy reloaders. IMHO of course. But that isn't the only factor or reason, there flat are rifles with chambers minimum enough to require those dies....I'm very happy you haven't found one yet in your own collection, not all of us take a chamber gauge to the gun store when we buy a rifle!
If you have a tool to show you what you are actually doing when sizing your brass, and not guessing, the small base dies are not going to be needed 95% or better of the time.