Bevel on sizer die


April 18, 2013, 08:56 AM
I have an old set of RCBS 9mm dies and the carbide sizer die doesn't have any bevel at the die mouth. Cases do not reliably feed into the die while using it on the progressive press. Is there any chance that I would be able to put a slight bevel in the die mouth using a readily available product? I was thinking maybe a grinding stone chucked in the drill, drill press or die grinder. I know carbide is hard so I am not sure if anything will work.

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April 18, 2013, 09:02 AM
Man, Carbide is hard as Hades and would probably ruin any tool you have to throw at it.
That said, it is also brittle and may explode in your face if you try to violate it.

May I suggest handling some other dies from different makers to see if another one would fit your needs? They are not that expensive.

April 18, 2013, 09:16 AM
It can be done but not easily. I would find a lathe to chuck the die up to, then use a diamond stone on a Dremel while it's turning. Light pressure. Then you may need to take some 600-1200 grit paper to put a mirror finish on it. If you have a large enough cone with one of the harder stones it may work. But I would want the part turning to give you an even cut. Some machine shops may beable to do it for you.

A better option would be contact RCBS and tell them the problem and see if they will fix it.

April 18, 2013, 09:19 AM
I create the same problem when using any sizer die in a Herter press if the ram is using the shell holder adapter. Bevel/radius? I do not know how old the die is, I do not know what press you are using, there is a remote chance the carbide ring has been installed upside down.

I will assume you are able to size cases if you align the case with the die, meaning the die works as designed when aligned, I have 4+ progressive presses, the case aligns with the die on all of them,

F. Guffey

Maj Dad
April 18, 2013, 09:51 AM
I have an old (but used only once or twice) Lee 44 mag carbide sizer that I bought and promptly replaced with a Hornady TiN sizer for that reason, and that it left a "waist" on resized brass. The newer dies from RCBS and other makers have a better radius (at least mine do) to avoid those issues. Watch on the for sale area here, and check the auctions - I have picked up dies and other stuff at great prices with some regularity.

April 18, 2013, 12:16 PM
I figured it would be a pain to do. I have been looking for a set of Hornady or RCBS dies in 380 and 9mm and as I'm sure you are aware they hard to come by these days. I happened upon a #16 shell plate for a LnL and used it as trade fodder for this set of RCBS 9mm dies. The dies are old and it didn't cross my mind about the sizer die mouth until I got the die and noticed that there was no bevel at the mouth. The sizer die works just fine but cases tend to hang up on the mouth of the die when using the Hornady LnL. I will probably just deal with the issue until dies start getting back on the shelf then pick up a new sizer die or another set. The set did come with a nice Lyman belling die, I have no complaints about the trade but next time I will know to ask about the die mouth and if the seater has both the round and SWC stem..

Jesse Heywood
April 18, 2013, 01:27 PM
Contact RCBS and tell them you have a problem. They will either rework your die or send you a new one.

You could fix it yourself if you have access to a lathe, which makes it far easier to hold the concentricity. But when RCBS will do it under warranty, why bother?

April 18, 2013, 04:16 PM

Diamond tooling is the only thing that works carbide.

If you have a small diamond coated rod you could try to break the edge.

April 18, 2013, 04:24 PM
I use a Green Silicon Carbide grinder wheel to sharpen carbide lathe bits.

What you need is a Green Silicon Carbide Dremel stone, then chuck the die in a lathe and spin it while grinding the edge to a more forgiving radius with the Dremel.


April 18, 2013, 05:24 PM
I've encountered a similar situation with a Lee 9mm Carbide die. Actually it turned out to be a combination of a die with very little taper, and a shell holder that didn't have any degree of tolerance to allow the case the self align. The shell holder was a Hornady, so I swapped it out for an RCBS and most of the issue was resolved.
But I work on a single stage, not a progressive, so I would imagine that is two different worlds.

April 19, 2013, 09:32 AM
I finally gave in and bought Dillon 9mm dies. Worth the extra $$ on a progressive press.
You could reshape the die mouth but it would be difficult to polish the carbide enough to leave a good finish on the brass without using several grades of diamond paste. Cheaper to buy new dies.

April 19, 2013, 12:03 PM
I tried to reshape the edge go one of my lathe bits with wafer disk in my 4" surface grander. It didn't even polish the carbide enough to tell it was even touched with a grinder after about half hour of grinding. It barely even cut the braze. Glad RC spike up because I was starting to believe it was impassable to screen this stuff. I doubt you find a shop that would even touch it if the did a whole set would be a 1/10 of the cost of having it done.

C.F. Plinker
April 19, 2013, 12:49 PM
I had one like that many years ago. A friend said he could do it if I bought the cylindrical green silicon carbide bits for his die grinder. I met him at the shop with a pack of five bits. He already had the lathe set up mounted one of the bits in a die grinder and went to work. It took him 5 minutes and complitely wore out one of the bits but he got the job done. He said that he had seen dies ruined by people trying to free hand the grinding because they couldn't get a good uniform bevel.

The bits weren't easy to find back then so I just left the rest of the package with him so he could do it for others. I was fairly sure that some of our other friends would need the same thing done to their dies because a bunch of us went together on a "group buy" on Dillon 300 presses.

April 19, 2013, 11:21 PM
If you call RCBS and explain problem, they will have you send the die back to them for adjustment.

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