Modify a Lee collet neck die

[Ian]

So you want to shoot cast bullets in your .30-'06 and don't want your necks sized to .306" on the ID, but you DO like using your Lee collet neck die, then make a new, larger mandrel and bore the top bushing to accept it.

Original mandrel measures .3055". New, stepped mandrel measures .3085" and steps to .300" to eliminate dragging the entire length of the neck.



The hole through the mandrel was very crooked so it needed to be trued anyway as well as enlarged a few thousandths. I indicated the part true, trammed between the chuck jaws to ensure it was true on both ends, and grazed it with a boring bar to true it up.



Now my case necks are swaged a uniform .309" on the ID, regardless of slight thickness variations.

 

[waco]

Nice work Ian! Pretty slick.

 

[Ole_270]

Good job Ian, I need to do something like that for the 308 and alter a 22 Hornet or similar for my 25-20

 

[Wasalmonslayer]

Nice work!
It sure is nice to have tools and inginuity!

 

[JWFilips]

In the past I had Lee's custom shop make a number of mine! But I sure like your taper a whole lot, Ian
Great Idea!
I did have my good friend and super machinist Rick Fiore make a custom one for me a few years ago to size my over worn Sauer & Son Mauser 98 cases Need a .333 bullet ( Lee could not wrap their heads around that request!) now I still use the 8mm collet die and sleeve but had to buy another mandrill housing and open it up to accept the over size mandrill rod! I had him make it without the decap pin because I knew that would be too much work ( he always did stuff for me for free so I liked to go easy on him) I do not mind decapping first with the Lee universal decap die Rick passed away 2 years ago of cancer ....miss him His machine shop was just 2 streets across from my house

 

[Ian]

I just did another little trick that helps these: Bushing the bottom of the collet sleeve. The bushing doesn't need to be tapered to match the case, just be fired case diameter in one place is all. The reason is the case is pushed all the way up into the collet before any pressure is put on the shellholder, so the case floats to center in the bushing just before the shellholder contacts the collet and puts pressure on it. Everything is nicely centered this way and there's no dependence on the flash hole being centered, or a tight fit on the decapping rod, to center the case. Without a close-fitting bushing, the case can be held considerably crooked as the neck is swaged to the mandrel and this is easily seen with a case concentricity gauge.

There's another trick that I've read about some of the CBS folks doing but not tried yet which involves grinding a taper to the top of the collet fingers (I assume while they're forced closed on a mandrel the size of the sized neck O. D. ). This modification leaves the mouth a little large or "pre-flared" and reduces further any work-hardening of the case mouth. I'm not sure I need that, but am probably going to try it anyway at some point.

 

[Spindrift]

Very good idea, and excellent execution!
Does this mean your Tikka has arrived? I think you’ll be happy with that rifle
I once bought a .303 brit mandrel (2$ or something), thinking along the same lines. It would be to short to decap, but would set ID to suitable diameter. When it didn’t fit through the hole in that thingy-on-top, however, the .303 mandrel took up recidence in some remote corner of my reloading bench. Where it probably still is, somewhere.

 

[Ian]

The thingy on top is actually quite drillable, even sandable. If you had the whole Brit die there's some chance you could have swapped both pieces, though I'm not sure that the length of the other piece would be the same. You could buy a cheap HSS chucking reamer on-line, or even an adjustable hand reamer set and ream the part out just enough to fit the larger mandrel. Or just sandpaper and a dowel if your time isn't worth much....but I bet it is.

 

[Ian]

Tikka should be here tomorrow, still need to hit up a buddy for his '06 chamber reamer so I can convert some Lee rifle charging dies to in-line powder-thru and seating dies. I need to cast some 31-188Gs for it, too.