Comments on: TECH TIP: Use Rubber O-Rings with Sizing Dies for Less Run-Out

By: Virg

Virg — Mon, 02 Jun 2008 22:02:27 +0000

Guess I’ve just been lucky. I’ve been using the Lee O-ring lock nuts for years on all my dies (Redding, RCBS, and Lee) for years with the above mentioned finger tighten technique with excellent results…with no loss of adjustment problems. Works for me.

By: Kent

Kent — Sat, 31 May 2008 02:17:32 +0000

With all due respect, repeatable settings are possible by indexing the nut, hence the die, to any chosen spot on the press. I use either a casting seam, or the 6:00 position, whatever. Try it, it works, every time.

By: jthyttin

jthyttin — Fri, 30 May 2008 20:52:57 +0000

Lee dies do not hold the adjustment, period. Of course you can try to work around their limitations, but it’s not going to work and replacing with decent lock rings is easier anyway.

And with German’s tip, you’d have to mark your press and die lock ring in order to be able to return to the same setting (instead of being forced to measure the sized cases against your chamber every time).

In the end, it boils down to the fact how much you want to control the length-wise sizing. 2 degrees error (1/180 of full turn) when adjusting dies is 0.01mm/0.0004″ in base-to-shoulder length.

By: Kent

Kent — Thu, 29 May 2008 23:52:45 +0000

Me, again. I neglected to add that the Lee rings hold the die adjustment just fine. With very few exceptions, I have been using Lee rings on most of my sizing dies for 20+ years without any of the perceived problems. You just need to tighten them snugly with your fingers, and loosen them the same way. The o-ring also engages the die body to hold your adjustment. You only get into trouble when you grip the die when tightening or loosening.

By: Kent

Kent — Thu, 29 May 2008 23:41:20 +0000

Big new deal, not. Lee Precision has been selling a die nut with ingegral o-ring for years. And yes, they do reduce case run-out when re-sizing.

By: Steve Clark

Steve Clark — Thu, 29 May 2008 17:38:05 +0000

I’ve suggested this technique to others and have been laughed at. Glad to see it posited here as something that can work for you, if you’re open to it.