Help Identifying Forming Dies

[Doc_Stihl]

Found these and had to buy them out of curiousity.

Size #1 is .570
Size #2 is .560
Size #3 is .550
Size #4 is .545

106485106486

Any idea what the parent might be?
What the end goal might be?

I'm going to email RCBS in the morning to find out.

[dbosman]

.416 Howell ?
Starting with a .404 Jeffery case from Bell.

[Doc_Stihl]

The 404 Jeffery case starts out @.544 at the base. That brass would fall right down to the rim. After looking at the 404 Jeffery though, these dies might form a 404 Jeffery. But what could the parent case be....

Might be on to something. 404 Jeffery brass is a couple bucks a pop....

[EDG]

Have you checked the actual diameters of each die on both ends?
I am wondering if they are tapered.
A .416 Rigby head is .590 but .045 is a long way to squeeze a single case.
It seems like they might be part of a universal set to reduce the head of most anything if you have enough of them.