Just guessing, but I think it meant to size the belted magnum brass back to factory specs just above the belt.
Twenty to thirty years ago there was a small company that made collet sizers for the same purpose, they may still.
Robert
Yup they are still around and they work very well https://www.larrywillis.com/
To the OP that is the first one I have seen.
2nd Amendment of the U.S. Constitution. - "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
"Before you argue with someone, ask yourself, is that person even mentally mature enough to grasp the concept of different perspectives? Because if not, there’s absolutely no point."
– Amber Veal
"The Highest form of ignorance is when you reject something you don't know anything about".
- Wayne Dyer
Got any more pictures? Is it 2 pieces or just one? The Larry Willis die is 2 pieces. I think at one time he had diferent companies trying out his design maybe this was one of them.
only a single die. I sent a piece of 300 win mag through it. The base did size. As most of the belted mags diameters are in common this must be what it is.
I have Redding die that is marked "300 win mag body 5L" It sizes the body only on cases that are shorter than the 300, I've used it on 300 win, 308 NM, 264 and 7mm mag. Wont work on the 338, only 30 cal or smaller. Comes in handy now and then..
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |