Old Lyman sizer die's

[DresserDan]

Did the older sizer dies [four hole] have O Rings on top? Why were they a step style die?

[zarrinvz24]

IIRC some did, some did not. I have a few with no o-ring and it works fine. I look the o-ring more as a solution in need of a problem rather than a necessity. I'm not sure what you are asking about regarding a step die. They are all the same and work the same, there were minor production differences. Addition of extra holes, addition of o-ring are the primary ones.

[Bent Ramrod]

The early ones had a step because they figured taking metal off the boolit was the way to size. Took a while before people realized that the boolit could be squeezed down evenly more easily than cut down, which could take more off one side than another.

They didn’t have o-rings at the beginning because they hadn’t been invented yet. (First appeared in the 1930s in aircraft, IIRC.) They relied on precise fitting to prevent lube squeezing out.

I usually don’t get leaks using the old style dies, but let an o-ring get pinched or mangled on the new ones, and a ribbon of lube comes oozing out before the grooves get filled.

I put the old ones in the lathe and polish the step out with 600 wet-or-dry and crocus cloth wrapped around a dowel. Doesn’t take much time; not much of a step. Then the boolits squeeze down to size just like in a new die.

[zarrinvz24]

I stand corrected! Thanks for the correction Bent Ramrod! I have never seen one like that.

[JonB_in_Glencoe]

Of the many Lyman sizer dies I have used, I've only seen one with a "step" in it. I honed the step out.
I have many older Lyman dies without the O-ring and I prefer them. They are a bit larger (OD) on the top and fit best in the older Lyman 45 lubesizer. The newer dies with O-ring, when installed in a 45 lubesizer, could be over torqued with the setscrew and actually become out of alignment, if the OD is on the small size of the given machining tolerance, but it's such a small amount, it wouldn't effect pistol boolits, but could be an issue with long skinny rifle boolits.

[DresserDan]

Thanks I was just wondering as I picked up a old lyman sizer die and was looking for info on it. Hope it works ok iin my RCBS?

[Bent Ramrod]

Most of them will interchange. Every once in a while I find one that doesn't, but it's very uncommon.