.357 Magnum Binding in RCBS .38/.357 Expander Die

GeoTrekr

GeoTrekr

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I'm having an issue with my RCBS expander die and my NEW .357 brass.

I managed to get through quite a few cases, but then it started taking more and more effort, to the point I'm bracing the press on the down stroke.

I took out the expander, and wiped it completely dry and tried again, but it only took about 5 or 6 cases and I was right back to where I started.

I tried lightly lubing the inside of the cases with a case brush with RCBS lube on it, and this seemed to help, though I needed to do this about once every 2 cases or so to keep up the effect.

I then pulled the expander out again, and coated it with a little RCBS lube, and tried again. This time I was able to complete about 8-10 cases before it started wanting to bind up again.

There is no way anyone with a progressive press is lubing up every second case just to run it through the expander, so I figure someone might have a good solution?
 
Could you be over expanding? The case mouth jamming between the plug and die body. You don't need to expand the mouth very much, just enough to easily insert the bullet. Just my .02.
 
Is the expander plug lock-nut tight, or is it working loose on you? Are you attempting to bell the case mouth too much, are your case mouths belled uniformly? The base of the bullet should "just" sit nicely inside the case mouth. Too wide a bell serves no purpose other than to shorten case life through over working the brass. The effort necessary to expand the case mouth should be minimal, less than seating a bullet or crimping. Even the little Lee "C" press performs the chore effortlessly. Don't contaminate the inside of the case with "wet" lube, instead choose a dry neck lube, I use Imperial Dry Neck Lube, but there are several to choose from. Having said that, I've never found it necessary to use dry neck lube when belling case mouths and reserve it for cartridges which require the use of an expander ball for resizing or for the cutter of my primer pocket uniformer when uniforming new brass that doesn't have any carbon deposit to provide lubrication.
 
vviking said:
Polish the expander button to a high shine, and dip each neck into a dry powdered lube ... I use the Lyman white stuff.
Click to expand...

This looks like it's going to be the most promising solution. The black coating that was on the expander plug is being scratched off, which I believe has left a slightly rough finish on the plug that is binding up the cases.

iceman2 said:
Could you be over expanding? The case mouth jamming between the plug and die body. You don't need to expand the mouth very much, just enough to easily insert the bullet. Just my .02.
Click to expand...

Nope, no way. I've adjusted the die to just barely accept a new bullet. Having said that, when I started encountering the binding, I experimented by adding/removing some expansion to see if it made a difference. No dice, it would still starting binding after about 5 or 6 cases.

Boomer said:
Is the expander plug lock-nut tight, or is it working loose on you? No. Are you attempting to bell the case mouth too much, are your case mouths belled uniformly? No, yes. The base of the bullet should "just" sit nicely inside the case mouth. Check. Too wide a bell serves no purpose other than to shorten case life through over working the brass. The effort necessary to expand the case mouth should be minimal, less than seating a bullet or crimping. The case goes into the die easily enough, it's coming out that's the problem. Even the little Lee "C" press performs the chore effortlessly. Don't contaminate the inside of the case with "wet" lube, instead choose a dry neck lube, I use Imperial Dry Neck Lube, but there are several to choose from. Having said that, I've never found it necessary to use dry neck lube when belling case mouths and reserve it for cartridges which require the use of an expander ball for resizing or for the cutter of my primer pocket uniformer when uniforming new brass that doesn't have any carbon deposit to provide lubrication. Neither have I. While I've only loaded 50 rounds with the setup before, I agree that the belling was the least resistive step of the whole process, which it should be, which is why I was so surprised when this started happening.
Click to expand...

mbogo3 said:
Are they carbide dies? Shouldn't require any lubrication............Harold
Click to expand...

Yes, they are carbide dies, and no, I didn't find it necessary to try any sort of lube until I started to worry about my brass not coming back out of the expander die.

After doing a string of 6 or so brass cases, one can actually feel the brass is coming out the die slightly warm from the friction. I completed my lot of 200 cases by taking the expander plug out every 5-6 cases, wiping it (and removing small brass filings), and replacing it. Lather, rinse, repeat.
 
This happened to me 2 nights ago reloading .357 and after a hour of trying everything you mentioned I changed my shell holder and presto, no more binding. May just be a fluke but I found that the lee shell holder didn't hold the brass square. I put in a RCBS and finished the rest of the batch (500) without a problem.
 
Timely responses to this thread, as I'm back doing a batch of 200 new Winchester brass, and lo-and-behold, I'm having the same issue. I spent an hour in front of the TV polishing up 2 expander plugs (I have a taper crimp and roll crimp set for .38/357, so I polished up both) with 600 grit sandpaper.

One plug has a fault. I'll try to illustrate:

Plug 1:

_____==/
(
------==\

Plug 2:

________/
(
----------\

Plug 1 has a part where it thickens before it gets to the sloped part. Problem is, after polishing both up with 600 grit sandpaper, they both bind just as much as the other. I have not tried the dry lube yet as I don't have any, but the part that bothers me is the many replies that state nothing extraordinary should be required, and little force should be involved. On the down-stroke, my press nearly wants to rip itself from the bench because it binds so tight on the plug. When removed, the plug has vertical lines of brass, some of which can be wiped off, the rest of which I'll probably have to sand off.

I know the progressive guys wouldn't put up with such a headache for simply expanding brass to accept a bullet, but is it possible that two RCBS expander dies are faulty? Is it a design flaw? I've never tried any other dies other than RCBS, so green is what I know; and right now green isn't working too well...
 
Just for arguement sake, try holding the brass tight against the shellholder on the upstroke.
Mine are RCBS too and like I mentioned before, it seems to be the shellholder causing my problem.
 
I changed the shell-holder - no change.

I re-sanded the expander, and I tried dipping the brass into graphite powder. It wouldn't stick too well, so I started breathing on the cases, then dipping them. This tended to get more on the inside, but also got a lot on the outside. When a fair bit of the graphite powder gets inside the case, it works quite smoothly, but it also creates a bit of a mess. It is also extremely slow.

I tried chamfering the inside and outside of the cases and running them through. This made no difference.

I have now dumped the last 50 pieces or so of brass into the tumbler, and I'm going to test if they run through better with a bit of treated corn-cob dust on them.

This is really frustrating because everyone I've talked to or asked looks at me like I have 2 heads when I describe the problem. Obviously this shouldn't be anywhere near this difficult, and I can't figure out what the hell the problem is. I'm hoping that it will get easier after the brass is once-fired, otherwise reloading .357 will be a very frustrating exercise (bad enough I'm doing it on a single-stage press).

If this means anything, I removed the plug to see how the sized brass fits on the plug. You would have to push damn hard to get it on the plug, at the risk of probably not being able to pull it back off.

Is it time to buy a new .357 die set from another brand? Any recommendations? (Before I resort to this, I'm going to contact RCBS first).

Thanks for the suggestions so far guys. Keep them coming, but also let me know what flaring the mouth on a .357 case should be like. From the sounds of things, it should be a cakewalk; just that filler step between re-sizing and seating, the only 2 operations that should take any kind of effort. From the sounds of things, expanding should just be a matter of moving the handle without any kind of force behind it (currently my experience is that pushing the brass into the expander is seemingly effortless, it's removing the brass where all the binding and effort occurs).
 
is the expander plug long or short? i have a 32 s&w long die set from dillon , they told me that i needed the long expander, because of loading wc's, didn't work worth a s--t, i had exactly your prob. switched to the short [ normal one in my mind ] & no more probs.
 
eh class said:
I had the same problem with new 38 super cases once , I found that if I threw them in my tumbler and ran it for a half hour or so they worked much better .
Click to expand...

DING DING DING We have a winner!

I tried the brass I tumbled a bit in clean media (I'm sure it doesn't have to be, but I just happened to change out my media after my last tumbling session), and the dusty brass was processed in no time. It made a horrible creaking noise both in and out, but effort was reduced at least 90% on the downstroke, and a bit on the upstroke as well.

I'd rather put up with a bit of noise than that messy graphite powder any day!

Thanks everyone for your suggestions, and I hope this learning journey is useful to someone other than my stupid self!
 
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