I have reloaded my 300 Win Mag cases enough times the case necks are splitting. I have a full length rcbs die for this caliber. These are the "cheap" ones that use an expander ball. I do not want to invest in bushing dies right now. My theory is to enlarge the neck portion of the full length die slightly so it doesn't overly reduce the neck diameter and over work the cases and cause them to crack. I just don't know how to enlarge it correctly--I am not a machinist with a lathe. Has anyone tried this? If not, any good ideas on how to do this? Goal is to resize the resizing die so case neck diameter only gets reduced as much as necessary. Seems expanded ball would have much less work to do on the way out too.
Anybody tried to modify neck portion of rcbs reloading dies?
- Thread starter pickjare
- Start date
AndyTaber
New member
I don't know if you are thinking of doing this yourself or hiring it done. Just my thoughts but you will need the equipment to hold the die perfectly in place or you will be introducing more runout on your necks than anyone deserves. A drill bit wouldn't produce the kind of finish this would require, provided you could find one in the exact size needed. That would leave you with buying a custom ground reamer to bore the hole. All and all i think a bushing die would be your least expensive option.
Sizing dies are hardened....or at least USEFUL sizing dies are hardened.
RCBS are hardened....they are not in any way "cheap" in the sense that any other brands are "better" or "more concentric" (they're ALL concentric) nor will any other store-brand make "more concentric" reloads no matter WHAT the innernet sez...
Concentricity of loaded rounds is dependent on TWO things, initial fireform and fit of die-to-chamber.
And the dies must be hardened.
Which RCBS are.
Consequently, you jam a reamer up in there and the results will most'n likely be , ummm, interesting.
But not satisfactory.
To open up the neck of a die it need be ground.
IMO
This grounding will cost more than a good (custom/fitted) die unless you know a GOOD machinist in a WELL EQUIPPED tool and die shop who's willing to work for beer money.
opinionby
al
RCBS are hardened....they are not in any way "cheap" in the sense that any other brands are "better" or "more concentric" (they're ALL concentric) nor will any other store-brand make "more concentric" reloads no matter WHAT the innernet sez...
Concentricity of loaded rounds is dependent on TWO things, initial fireform and fit of die-to-chamber.
And the dies must be hardened.
Which RCBS are.
Consequently, you jam a reamer up in there and the results will most'n likely be , ummm, interesting.
But not satisfactory.
To open up the neck of a die it need be ground.
IMO
This grounding will cost more than a good (custom/fitted) die unless you know a GOOD machinist in a WELL EQUIPPED tool and die shop who's willing to work for beer money.
opinionby
al
243winxb
Member
A wood dowel and emery paper will open an old 1980's RCBS 223 Rem FL die. Not hard at all, sorry AL. 
Having done it, i dont recommend it. https://thefiringline.com/forums/showthread.php?t=548810
Having done it, i dont recommend it. https://thefiringline.com/forums/showthread.php?t=548810
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A wood dowel and emery paper will open an old 1980's RCBS 223 Rem FL die. Not hard at all, sorry AL.
I read the thread, I'll agree that some over there have done it.
I have done it, with emery paper as well as with lapping grits and with a carborundum hone.
VERY hard to take out the necessary 4-6 thou without eccentricity/belling/flaring, and very time consuming.
Reading your snide remark ("Not hard at all, sorry AL"
)I have trouble believing you've done it.I'll stand pat, it'd best be ground out (honed) with a machine. And those die-makers who'll hone to a custom size for 10-20 bucks??? That's a GREAT deal! I don't know that RCBS offers this service.
Thanks for responses--now I know I'm not the only one to think of trying it
Ya thanks for your time. It's something I thought was a good idea, then thought about it overnight and realize now I should get the right tool for the job. If they weren't made of hardened steel it would be a different situation. Course then the die wouldn't last and we would always be buying additional dies anyway.
Ya thanks for your time. It's something I thought was a good idea, then thought about it overnight and realize now I should get the right tool for the job. If they weren't made of hardened steel it would be a different situation. Course then the die wouldn't last and we would always be buying additional dies anyway.
Yes, I will buy new brass. I have other brass and will throw any cracked ones away, anneal the rest. I just want the new stuff to last as long as possible. And I thought if I could make the neck portion of this die a little bigger that would be good. I see now that because they are hardened there's nothing I can do. Interesting about the neck turning comment because I have 50 pieces of Nosler that I did neck turn--not to fit my chamber but to create more even neck tension. Anyway none have cracked, however, they haven't been reloaded quite as many times (6 for nosler, 8 for Winchester). I will get bushing type dies and be done with it. Thanks again for the help.
jackie schmidt
New member
Most mass produced sizing dies are manufactured from carbon steel and are case hardened. The case hardenning will usually be around .005 to .008 inch thick. The steel underneath is dead soft.
You can purchase a carbide chucking reamer that will cut it. It will follow the hole that is there.
But of course, you need a lathe to chuck the die up truly straight. I have done this, so I know it can be done.
Expect to pay over $100 for a solid carbide chucking reamer.
So, follow Wilbur's advice in post #9.
You can purchase a carbide chucking reamer that will cut it. It will follow the hole that is there.
But of course, you need a lathe to chuck the die up truly straight. I have done this, so I know it can be done.
Expect to pay over $100 for a solid carbide chucking reamer.
So, follow Wilbur's advice in post #9.
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XBBR Shooter
New member
Why not anneal the necks? It should be something you are doing anyway. The necks will stop splitting.
Just started
Until I spotted the first crack I haven't ever needed to anneal, but now I am annealing everything. I don't have a machine, just watched the process on you tube and then try to duplicate it as close as I can--time will tell I guess. But it seems to me that I also need to start using a bushing style die opposed to the expanded ball type. So many different considerations within reloading aren't there? Thanks.
Until I spotted the first crack I haven't ever needed to anneal, but now I am annealing everything. I don't have a machine, just watched the process on you tube and then try to duplicate it as close as I can--time will tell I guess. But it seems to me that I also need to start using a bushing style die opposed to the expanded ball type. So many different considerations within reloading aren't there? Thanks.
Make sure you use some tempilacque.
I would use it at least initially on every case till I was sure of the setup.
The 'exact' temp is often sold out but you can just go up a few degrees and find what is available.
Just a question..
How many times can this brass be reloaded? Are they splitting due to the die or they just plumb wore out? Is the Norma better than Lapua? Thanks
LASER
How many times can this brass be reloaded? Are they splitting due to the die or they just plumb wore out? Is the Norma better than Lapua? Thanks
LASER