I recent bought a Lyman carbide neck sizing die for .204. I think I have a problem with it, but being fairly new to reloading I wanted to ask the experts. The sizing stroke is not as smooth as I would have thought and the final result is a neck that is too big for the bullet. The bullet can be more or less dropped in the case.
It is my determination that that the sleeve that sits right before the button is too big. I measured .208 for the diameter of the sleeve and .203 for the diameter of the button. The button should be the sizing mechanism, not the sleeve which is suppose to only act as a spacer. I am guessing I need to call Lyman and have them send a replacement, or am I missing something?
There sounds like there is a description and nomenclature problems here. Rifle resizing dies do two steps at one time, they resize the outside of the case on the up stroke and then expands the mouth on the down stroke. The expander button is part of the decapping rod.
A neck sizer dies only resize the neck portion of the bottle neck case. Generally, there is an expander button to expand the case mouth to the correct size. This expander is the same as with the full length sizing die and installed on the decapping rod.
These types of dies reduce the case neck smaller than needed and the expander ball expands the neck back to the desired size for proper neck tension.
There is a category of dies called bushing dies, or something similar, where one can replace a bushing of different inside diameters in the neck area of the die. These dies do a minimum of resizing to the desired size and generally do not need an expander button.
Carbide rifle resizing dies are few and far between, very expansive, and generally used only by high volume reloaders. They still require the use of case lubricant. (Note, carbide pistol resizing dies are a different kettle of fish and are widely available)
There are kits available for rifle dies that have carbide expander buttons. Lyman and Redding make some. I find they still work better with a bit of lubricant.
So, to answer the OP's question, it sounds like the cap that holds the carbide expander button on the decapping pin may be too big. It should not touch the case mouth, ever. Only the expander button should contact the case mouth and only after the neck size has been reduced by the resizing die.
I would give Lyman a call or reduce the size of cap.
Hope this makes sense.
