Question on LEE collet neck sizing die

[Idaho Mule]

I have some fatter throated 303 Brits. and am wondering if the Lee collet neck sizer die might help my brass last longer by not necking it down so far as my current rcbs size die does. Is the Lee collet die adjustable, as in can I size the neck to accept a .313 boolit, and then adjust to accept a fatter .316 boolit? Thanks in advance guys, I know someone here has played with this and can answer my questions. JW

[texassako]

You can pretty much size down as far as you need to, or in your case only as far as you want to. It is all about how firmly you pull on the press handle with a strong pull sizing down as far as the mandrel will allow and a light pull sizing the neck less. There is a learning curve to figuring out how much pressure to apply if you are not sizing as far as the die will allow.

[Idaho Mule]

texassako, thanks, I kinda thought that but did not know for sure as I have never used one before. JW

[petroid]

I have looked into the collet dies but don't own one. From what I gather, the collet squeezes the neck against a mandrel. think factory crimp die with decapping rod through the center. the mandrel is machined to a specific diameter which the collet squeezes against. the more you screw the die in the more the collet squeezed until the brass is tight against the mandrel. there is a certain amount of spring back which means that you can adjust the collet to squeeze not quite against the mandrel up to all the way tight against it which will give you a range of neck sizing options. what that range is will depend on the od of the mandrel.

[462]

I use the .303 British die to get .316" neck tension for .318" boolits for a couple Enfields. Using the same die, I adjust it to get .314" neck tension for a .316" Argentine Mauser boolit.

I start by measuring a fired case's mouth, using an inside micrometer. Then, thread the die into the press until the desired amount of neck tension is achieved, when the press ram is all the way up. I found that this method eliminates guessing how much pressure to apply to the press handle.

[geargnasher]

+1 to what 462 wrote. Set the depth of the die for your adjustment. Be sure and lock the die firmly when this is reached, as the adjustment you get at 14 threads-per-inch is rather "coarse" and a tiny bit of die rotation = a lot of difference in how much neck sizing you get.

Ideally, one would get mandrels made for different desired neck inside diameters and size firmly against the mandrel, but it isn't necessary.

Gear

[hendere]

I don't know anything at all about this subject but I noticed this earlier today while looking for something else. Would this maybe help?
http://www.titanreloading.com/consistent-crimp

[Idaho Mule]

Thanks 462 and gear, that sounds fairly simple. I think I will buy one of the Lee collet sizing dies now. JW

[MtGun44]

Lee collet is a really great tool. My first one increased the accy of my 7x57 loads noticeably,
straighter necks - which set me on a learning curve for straighter necks in all my ammo,
so all is now better than it was 20-30 yrs ago.

Bill

[EDG]

Most .303 brass fired in a Lee- Enfield will separate the case heads long before the necks crack.