Need to shorten a RCBS seating die

[40-82 hiker]

I need to shorten my RCBS seating die, but I do not have a lathe. I'm pretty sure I can do an absolutely horrible hack job on it with a grinder and then a Deremel tool to chamfer the opening. However...

To wit: I'd like to ask if someone on CB, or known by someone, could use a lathe or appropriate tools to shorten this die for me. Can trade or $$.

Or, alternately, give me some idea(s) on how I can do this with normal tools, and end up with something better than I can envision at the moment. Then again, maybe that is good enough. Looks don't really get to the heart of something, after all.

Thanks,
Bob

[ReloaderFred]

If you only need to take off a few thousandths, you can take that off the shell holder, which is the easiest, and cheapest, of the components. On the other hand, if you need to take quite a bit off, then it's going to take a machinist to do the work.

Hope this helps.

Fred

[Wally]

I've modified a few dies, shortening them, using a grinder. Just go slow and quench in cold water; use a caliper to keep the bottom flat. I used a fine wheel so I didn't remove much metal too quickly. I then did a final polish with 400~600 sandpaper and it looked quite "professional".

[Ballistics in Scotland]

I need to shorten my RCBS seating die, but I do not have a lathe. I'm pretty sure I can do an absolutely horrible hack job on it with a grinder and then a Deremel tool to chamfer the opening. However...

To wit: I'd like to ask if someone on CB, or known by someone, could use a lathe or appropriate tools to shorten this die for me. Can trade or $$.

Or, alternately, give me some idea(s) on how I can do this with normal tools, and end up with something better than I can envision at the moment. Then again, maybe that is good enough. Looks don't really get to the heart of something, after all.

Thanks,
Bob

I've always thought that the best machine for the amateur tinkerer is a belt sander, capable of using really aggressive belts. Unlike some other shooting expenditure, it can be useful for all sorts of other things as well. A bench mounted one with an angle-adjustable one to hold the work against is best, but a hand-held one can be fixed in a vice when you need it that way. It would remove metal from the bottom of a die quite easily.

I think hand and eye will do for making the new bottom square with the die axis. But if you have any doubts, a die nut with a locking screw will keep you right. Drawing the heat treatment isn't that important for a seating die, but it is something to watch out for with a sizing die, like the one I shortened to make .255 Jeffery from .25-20. You could do the chamfering with several grades of abrasive paper wrapped around anything hard and conical. If it doesn't shave or score the brass, it's chamfered.

[jsizemore]

A couple nuts locked against each other on the die can be a good guide to reduce the dies length. Chuck it in a vice and start filing. Check often.

[40-82 hiker]

Thanks to all. I'll have at it myself then. Using the suggestions given, I'll use a lock nut as a guide for flatness, and find something to chamfer with decreasing grits.

I'm thinking the chamfering will be the most important part of this to get right. I'll keep the die cool...

Thanks again.

Bob

[JimB..]

It’s pretty easy to keep something like this reasonably flat if you chuck it in a drill and spin it as you grind. I’d put a couple nuts on and then glue a sacrificial fender washer to the bottom nut as an indicator. Honestly I’d do it on a wet stone grinder, but a regular grinder of belt sander will do just fine. Coarser grit will cut a little cooler, then finish with a file or a stone.

[JimB..]

For the chamfer you could polish it with a purpose-made wooden peg and lapping compound. Put a piece of wood in the drill press, file and sand it to shape and size, add compound and then run it against the die.

[BK7saum]

I had to remove 0.027" from a sizing die to bump the shoulder. Used a belt sander and measured with calipers off of the flat top to get it square. Looks good. Can't tell it's been shortened

[country gent]

A way to recut the chamfer true and even is use a ball marble or other round surface and valve grinding compound. If you want the big radious the maker cut then rough it in close with a dremil tool and the finish with the ball and compound. some flitz, simichrome or tooth paste gives a nice final polish. The big radius is nice on progressive machines but on a single station a lot less can be used as long as there are no sharp edges.

[dikman]

BiS, I agree, over the years I have found a belt grinder to be invaluable - steel, wood, plastic, brass, leather, antler. Not much I haven't used it on.

[Wolfer]

Like Jim B I usually try to chuck in a drill and spin while I'm grinding. A carriage head bolt and valve grinding compound is what I used to cut a crown in sawn off rifle barrels before I got a lathe.
I still would if I didn't want to pull the barrel.
I'd be happy to do it on the lathe for you but this is very doable with minimum tools and a little bit of handy.

[15meter]

If you only need to take off a few thousandths, you can take that off the shell holder, which is the easiest, and cheapest, of the components. On the other hand, if you need to take quite a bit off, then it's going to take a machinist to do the work.

Hope this helps.

Fred

What he says, I have ground down a couple of shellholders to allow me to get a case in just a little further to set a shoulder back during case forming from a donor cartridge to the target cartridge. If it is more than a couple of thousands than you are stuck with grinding the die it self.

Just curious, why do you need to do this, usually the seater die is still above the shellholder when seating/crimping the boolit.

[40-82 hiker]

Just curious, why do you need to do this, usually the seater die is still above the shellholder when seating/crimping the boolit.

Quick answer (the battery is about to run out): I need to increase the clearance between top of boolit and bottom of seating die on my Classic Turret Press (with boolit seated way out to fill chamber throat, and die screwed way in (sic, down) for crimp). Boolit is hanging up on die mouth and jamming the turret when I increase crimp to the extent I want. 30-06 is a long cartridge for the CTP, but this is the only problem I encounter, and only with this one boolit. RCBS seating die is "84" manufacture, and it works great, and can't afford another. Use it for my fart loads, which are very accurate and allow me to shoot when back is too painful. 'Cause of my spine/pelvis injuries, I need to use the CTP to get enough loaded up in the time I have before my back gives out. Gone are the days of the Rock Chucker for me...

Thanks to all again. I'm going to tackle this starting tomorrow, hopefully, if my back is working. Love this kind of stuff! Uh-oh... Battery about to shut this thing off.

Bob

[40-82 hiker]

Sighted enemy and sank same!

This was actually an easy project, but you all already knew that. I ground the die down, chamfered the mouth of it, and it is back in the turret. As to the chamfer, I tried to scratch/cut a plastic Bic pen, a brass case, and a boolit. Can't even make a mark, expect for the shiny "track" left on the boolit, contrasted to the slight frost.

I put a lock ring on it as suggested, and just held it flat against my right angle grinder wheel, moving it around and changing the rotation frequently. The lock ring was a great suggestion, as it allowed me to have a reference for square, as well as depth. I wrapped it in a wet rag to control heat. Then, I used my valve grinding compound I have to open molds to cut the chamfer. I polished the ground face a little with the valve grinding compound, but I still left some grinding marks, not bothering to polish it to a shine.

This project cost me zero! I could not be happier with the results. I took off around 0.18", not wanting to have to mess with this again. My measurements showed I could have taken some less than that and probably been okay, but I just went ahead and took it down near the threads. This is a VERY long die, and that 0.18" will not be missed.

Thanks again to all for the suggestions, and offers to help.

Bob

[sawinredneck]

Glad you got it sorted out.

[Kenstone]

Sighted enemy and sank same!

This was actually an easy project, but you all already knew that. I ground the die down, chamfered the mouth of it, and it is back in the turret. As to the chamfer, I tried to scratch/cut a plastic Bic pen, a brass case, and a boolit. Can't even make a mark, expect for the shiny "track" left on the boolit, contrasted to the slight frost.

I put a lock ring on it as suggested, and just held it flat against my right angle grinder wheel, moving it around and changing the rotation frequently. The lock ring was a great suggestion, as it allowed me to have a reference for square, as well as depth. I wrapped it in a wet rag to control heat. Then, I used my valve grinding compound I have to open molds to cut the chamfer. I polished the ground face a little with the valve grinding compound, but I still left some grinding marks, not bothering to polish it to a shine.

This project cost me zero! I could not be happier with the results. I took off around 0.18", not wanting to have to mess with this again. My measurements showed I could have taken some less than that and probably been okay, but I just went ahead and took it down near the threads. This is a VERY long die, and that 0.18" will not be missed.

Thanks again to all for the suggestions, and offers to help.

Bob

Too late for the party...
The dia. on most seating stems are small enough to be chucked in a drill to spin the complete die.
Clamp the drill in your bench vise with the die in the chuck, tape or clamp the drill trigger on, and have at the spinning die with that angle grinder.
The bevel/chamfer on the ID can be easily cut with a dremmel type tool, with a spinning die too.