I think that the problem is that, after you resize the neck of an empty case, seating the bullet expands it a little. A die that pushes back the shoulder of a loaded round also tries to resize the neck, but the bullet prevents this and the round can get stuck, unless you use a body die for a larger case as MD suggested.
No way would I try this, even with lubricant.
The clearance of a bullet seating die is a lot more.
How many rounds are involved? Why not just pull the bullets?
Not necessarily so. Many times I've used a Redding 308 Win. body to brush back shoulders of loaded 308 Win rounds. You should check for clearance and mine has plenty. MD's suggestion was for
if there was a tight situation. Then you should use a die for a larger necked cartridge.
