I recently acquired a couple of Lyman dies sets (the 310 type dies) in .270 and .243. Each set has the standard 310 sizing/decapping die as well as the seating die. They also each have another die (the one on the right) with them that is standard size with an rcbs style locking ring. The top is hollow and it fits in a standard size press. The only identifying marks on the die on the right is the caliber designation (i.e. .270 win).
Is this some type of body/bump die designed only to set the should back?
Thanks,
Jason