Home Forums Reloading Big Game Rifles Modifying a Lee collet neck sizing die

Recently I put out a request for someone to modify a Lee collet neck sizing die to work for a .250 Savage AI. A standard .250 Savage die would work but Lee quit making them and they are scarce as hen's teeth.

Nsaqam modified this .257 Roberts die to work with a .250 Savage and I am happy to report it works perfectly.

Lee collet dies all use the same length body and decapping mandrel (for most cases, .223 sized use a shorter setup). The collet sleeve and the collet itself are cut to fit that one die body length. A shorter collet uses a longer sleeve and vice versa.

What nsaqam did was to cut a spacer to move the two pieces down for the shorter .250 Savage case, then machined off the bottom of the collet to keep the same overall length. You have to move that little shoulder on the collet as well. There is a corresponding lip on the inside bottom of the body to keep the collet from falling out.

In this picture the die on the left is for a .308, you can see the longer sleeve. The die on the right is the modified .257 Roberts die, the spacer is just under the cap.



A closer picture of the modified die.



This technique can be used to make any Lee collet die work for any shorter case within the same caliber. We could have used a .25-06 die for this. You just have to keep the collet/sleeve/spacer total length the same as the original collet/sleeve length.

A big tip of the hat to nsaqam for coming up with this and doing a very professional job on the machining.




Now, of course, in the meantime, I took my .250 AI to the gunsmith to fix a little problem with the extractor and probably won't get it back for at least two weeks. So now I have these wonderfully neck sized AI cases and nothing to shoot them in!