How to prevent taper crimp brass scratching?

[45crittergitter]

Hi folks, when taper crimping my .45 ACP loads with an RCBS die, I commonly get some brass buildup or "plating" inside the taper crimp die, which then causes minor but persistent scratching of the cases. The brass is a bear to scrub out of the die, and reoccurs pretty soon. Does anyone have a good prevention for this?

 

[Trent]

OK.. taper crimp (I'm assuming you are using a seating die screwed down to provide a light taper crimp).. it should remove NO brass during the process, so my question is where's the brass coming from?

 

[Trent]

(FWIW, I've been using the same RCBS carbide dies set w/ light taper crimp for 10+ years - 50,000+ rounds - and I've never had an issue with them)

I disassemble them for cleaning every 1000 rounds or so - but never had to use anything harsher than a plain old q-tip.

 

[noylj]

1) separate the seating from crimping and buy a Lee taper crimp die
2) chamfer your cases lightly inside and out
3) reduce the flare/belling if you can
4) thoroughly clean the die
5) don't use nickle-plated cases

 

[Walkalong]

You can polish the internals, although the RCBS dies are usually nicely polished from the factory, but it sounds like you are over crimping. It is not uncommon to get a little bit of brass etc in the die, but it should not build up enough to be a problem for thousands of rounds.

never had to use anything harsher than a plain old q-tip.

Yep, just wipe it out with a Q-Tip or Kleenex etc.

 

[rfwobbly]

I agree with the others, you seem to have your crimp die adjusted incorrectly. In a combination seating/crimp die, the crimp is set first (using the position of the die body [blue]) and then locked into place with a good lock ring. Then the seating depth is set per the bullet being used, by way of the [red] seating stem. It's easy to see in this cartoon...



Your RCBA dies should have a set screw to keep the lock ring in a fixed position to make it possible to remove the die from the press and return it to the same position on the next loading session. If this is not working for you, then try a Hornady lock ring, which has been voted best lock ring here on THR.



Finding the right crimp diameter is easy. Simply seat a bullet into a case with no flair (belling) and measure that. On cases that used flair, the taper crimp die should erase the belling and return the case back to that same diameter. No more, no less. And remember: taper crimp only affects the last ~1/32 inch of case, right at the mouth.

See if that doesn't help.

 

[rcmodel]

My guess is you already have brass galled to the inside of the die. Which in turn continues to scratch other cases, and deposits even more in the die.

You can't clean it out using normal cleaning methods.

The best way is to polish the die and start over.
Split a wood dowel and use a flap of 400 or 600 grit black emery paper & a cordless drill.

It will not hurt the die, but it will get the embedded brass out rather quickly.

rc

 

[Steve in PA]

I concur, you have your dies set up wrong. I've been reloading semi-auto cartridges for over 20 years, using nothing but RCBS dies and I have not encountered anything like you describe.

 

[gamestalker]

Inspect that die for a possible fractured carbide sizing ring. I borrowed a die from a buddy that had a fractured ring, and it did the same thing as what your describing. Some carbide dies are not supposed to make contact with the shell holder, specifically for this reason. Carbide sizing rings are very brittle.

 

[rcmodel]

I think it's his seating / taper crimp die he is talking about.

It wouldn't have a carbide sizing ring.

rc

 

[popper]

Flat based bullets, not using a flare will shave copper from the BULLETS, deposit on the seating die which shows up on the crimp - or crimping and seating further will shave copper.

 

[Red Cent]

Also reads that someone may not clean fired brass.

 

[p5200]

I will be ordering some 9mm Luger dies next week from what most people tell me, I should get the LEE 4 Die set so I guess that's what I'll try on my Forster Coax/Bonanza.

 

[noylj]

If, and only if, you plan to shoot lead, you may want the 3-die set and a Lee taper crimp die.
Also, if you want to seat and crimp at the same time, first you seat the bullet, then raise the seating stem, then adjust the die body down to you "desired" crimp, lock the die body down with the lock ring, then turn the seating stem down to touch the bullet.
Trust me, separating the two steps is so much easier and, for me, much better.

 

[Striker Fired]

Hornady makes a better set,the seater has a drop down floating guide that helps align the bullet better.I have both the Lee and Hornady and I don't use the Lee set other than the FCD on certain loads.for seperate crimping I use all Dillon.

 

[p5200]

Isn't the fourth die in the LEE 9mm set a Lee taper crimp die? I may be confused here this will be my first pistol loading.

 

[noylj]

The fourth die is their factory crimp die.
This die makes a fantastic taper crimp. I really like the crimp on this die. However, if using over-sized lead bullets (such as 0.358" in your 9x19 due to the barrel groove being 0.356-.37"--which isn't that uncommon), the sizing of the case (which only brings the down to just under SAAMI minimum chamber dimension and not as much as the sizing die) can swage the bullet down and you will have a bunch of rounds that are inaccurate and will lead your barrel. I have not ever experienced this, but it is a possibility.
Many people do not properly expand the case--all they do is flare/bell the case mouth. This means the bullet is being squeezed into a "hole" that is more than 0.003" smaller than the bullet diameter. If loading jacketed bullets, you will almost always get a case bulge where the bullet has not seated striaght and has produced a case bulge where the case wall is thinnest. Rather than use a correct expander, they go with the Lee FCD to smooth out this bulge.
The thing is, if you are reloading properly, the post-sizing will not even touch the case. However, for action pistol shooting, an inaccurate round is MUCH better than a round that fails to chamber.
As I said, I don't thing there is a better crimp die than the Lee FCD for either pistols or rifles, but you have to be aware of what is going on if you are loading over-size lead bullets. If you notice that almost all your rounds require the post sizing, you should be looking at the expander die to be sure that it is opening up the case ID, over the length that the bullet will be seated, to 0.001-0.002" less than the bullet diameter. Any more, and you are not expanding the case enough.

 

[45crittergitter]

Thanks for all the replies, folks. Let me clarify. I'm not talking about sizing or seat/crimping. I'm taper crimping with a dedicated taper crimp die, AFTER a separate seating step with only enough crimp in the seating step to remove the case flare. It is a taper crimp die, not a seat/crimp die. However, my OP was in error in that it is a Hornady, not RCBS taper crimp die. All the brass is vibrator cleaned prior to loading. Probably 15% of the brass is nickel plated. The build-up in the die appears to be brass, not nickel. popper may be on to something - it is possible that it's bullet jacket material, but I do flare the cases. I will watch for that next session. Please keep the ideas coming.

 

[45crittergitter]

Bump.

 

[rcmodel]

See post #7 & 8, again.

rc

 

[45crittergitter]

My dies are not "set up wrong," and I can clean them out with a bore brush, patch, JB cleaner and drill motor so the problem disappears - for a while. I only have this problem with this one caliber and this one taper die. I may try even better cleaning as you suggested. Thanks.

 

[rcmodel]

I didn't say they were set up wrong.

I said to polish them with a slotted dowel, a flap of 400 or 600 emery paper & a drill.

rc

 

[gamestalker]

My bad RC, seating die yes!

 

[Seedtick]

I may try even better cleaning as you suggested. Thanks.

Is the finish on the inside of the crimp die rough?

You may need to do more of the polishing part after you clean it out again. If you stick with the finer grit paper like rc suggested you won't wallow out the hardened die. The slicker you get it the less likely it will be to gall up again.

Seedtick

 

[45crittergitter]

Posts #8 & 20 said the dies were "set up wrong." That ain't the problem, and I don't see how it even could be the problem. I haven't worked with this one any more, but will try the polishing thing. Thanks!