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BigboreShooter
04-25-2023, 07:13 PM
Anybody have any luck opening up rcbs/Lyman bullet sizing a few thousands?
BigBoreShooter

megasupermagnum
04-26-2023, 12:26 AM
Yes, same exact method as opening up a Lee die. I think the punch pushes right out the top, then you have a die that looks just like any push through.

Assnolax
04-26-2023, 12:43 AM
My buddy ran a flex hone through a star sizer for me and opened it up a a half thousandth. Probably work the same on any sizing die.

45DUDE
04-26-2023, 01:50 AM
What size? It would leak unless you had an oversize piston. You could make it bigger and push through and pan lube.

stubshaft
04-26-2023, 05:35 AM
I've opened one of my RCBS dies .0015" and it does not leak. I use LBT Blue in it and it is stiff enough to resist leakage, although I have used White BAC and it did not leak either.

To open it up I used a split dowel and 600 grit wet or dry sandpaper.

hc18flyer
04-26-2023, 06:52 AM
I have used 'stubshaft's` method. Go slow , check often. Easy to get too large. hc18flyer

country gent
04-26-2023, 08:03 AM
It can be done and isnt hard to do. The ones I have done were roughed up to close to size then finished with a lap or the hone at work. A lead or brass lap for finishing gives a great finish. A wood dowel with 4 cuts 1" deep or more and a wood screw can be used in a bind to finish. The screw will expand the end and make it snug. Apply the compound and work at low rpm and high feed back and forth, occasionally snugging the screw to bring the lap back into tension.

When to this point the goal isnt so much metal removal but finish. You can get a very good finish and remove the high spots left from roughing. I use a very fine diamond compound but jewelers rouge and other fine polishes will work also.

Ar some point you may have to replace the pin with a bigger one this will depend on lube heat and pressure being ran

HWooldridge
04-26-2023, 09:05 AM
The dies are hardened to a fairly high Rockwell value, so grinding/honing is about the only way. I once tried to run a reamer thru a SAECO die and it just laughed at me.

Just make sure you clean off all of the grinding compound - wouldn't want to leave any grit that might transfer during lubrication.