I am having difficulty sizing some virgin 25-20 win brass.The cases crush on the expander ball.The dies are used RCBS and appear to have seen little use.I am using imperial die wax and mica on the case mouths,what could be the problem?

I would take the dies apart and make sure that nothing is stuck in there. then I would make sure all the case mouths are round and not oval. My first step would have been to put the cases through the resizing die even though they are virgin cases so the necks should be round.
Then use a deburring tool inside and out.
If that doesnt work then the expander ball might be too big or have a spot on it that is catching the cases. Hope that helps, good luck.
Of course you might be talking about your sizing die. In that case I'd make sure the dies are clean. and then maybe take a 223 case and use it to expand your cases mouths just enough so that they go onto the expander ball and into the die without getting crushed.

[This message has been edited by RMiller (edited 12-13-2001).]

If the dies are used I think someone has put the wrong expander in possibly while they were cleaning the dies. If you have a shop near you take the die down and compare it to a new one. luck hotdog

I have no experience with this caliber, so I can't give any specific information about it. But here are some things I suggest:

1. Unscrew the expander rod from the die and remove it. Then examine the expander plug to make sure there is no burr or other obstruction on it. Also make sure that the die has the correct expander plug (i.e. that it hasn't somehow gotten a wrong -- especially a too-large -- expander for this caliber installed on it).

2. Try lubing your cases with Lee case lube. I put some on a cloth and rub it lightly all over the outside of the case. Then I put some on a cotton swab (Q-tip) and swab the inside of the case neck lightly. After I'm finished sizing I clean the outside of the cases with Remington Bore Scrubber, and I swab the inside of the case necks with a dry cotton swab.

If you ascertain that the expander is as it should be and that the cases are lubed properly, but you still have the problem, I'd send the die back to RCBS and explain to them what is happening and ask what they think the problem is and how it might be corrected.

[This message has been edited by LE270 (edited 12-13-2001).]

The 25-20 is one of the weaker case designs in common use. I've no experience with this case, but I do reload the similar 32-20 (for an old Colt revolver).

Presuming that the RCBS die checks out, and the case mouths are close to round and have a small chamfer here are some suggestions that might help.

1. Operating the press very slowly, wiggle the case a bit as you raise the handle to be sure that the expander ball is centered. You've probably tried this.

2. If use of the standard expander ball fails you could remove it from the full length sizing die, substituting a .22 or .24 cal expander (to hold the decapping pin), and expand the necks with a long tapered expander mandrel of the sort that Sinclair sells.

3. You could do away with using the dies to expand the cases entirely (you have trouble because you are using virgin brass). To do this you would use the very light charge of fast powder/cream of wheat trick. Don't use a bullet, the sole purpose is to let the case expand. After doing this, full length sizing should be much easier. The sizing button will clear the case when it enters the die, it will size the case as it leaves the die.

Bob

[This message has been edited by bfoster (edited 12-13-2001).]

There must be something wrong with your expander, did you measure it?? .22H, .25-20, & .32-20 are all frail cases but should pose no problems like that.

I would bet that you have once fired factory brass with a crimp...You probably need to inside chamfer the cases and perhaps trim them...then resize, it's a common phenominum, with weak tapered cases. Mic the expander ball, you may have to turn it down a thousands or two.

------------------
Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

I recently acquired a .25-20 and have loaded a few rounds under exactly the same conditions -- brand new brass and RCBS dies. I haven't experienced the same problem, so my guess is that either you have the wrong expander button in your used die or the design of the button has since been modified by RCBS. At any rate, a replacement button should cure your problem. You might also try grinding a slight taper on the one you've got.

Not that it's relevant to your situation, but the mouth diameter of once-fired brass would be measurably larger than virgin brass (the crimp is irrelevant), therefore less likely to catch on the expander and crush. I guess Ray is out wandering around in the bush again.

Stonecreek, you are in error with respect to the crimp. At the pressures of this round, the crimps don't iron out worth beans. JMO, Dutch.