I haven't reloaded for my 6.5 Swede in many years, but the time had come. So, I hauled out my set of Lee dies.......still in the old round plastic container......and was mystified by THREE dies instead of the expected two. I have the usual sizing/depriming die, bullet seating die and the third is marked "Lee 6.5 x 55 B1". It has a high polish inside and the upper end is threaded as if it should accept an expanding plug, or something similar. It's NOT a collet die.......those hadn't been invented when I bought this set......so what the heck do I have here??
Note: I may have loaned the set out to someone in the past, can't remember. Maybe they gifted me with the mystery?