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N2Abyss 03-25-2009 04:46 AM

RCBS Die Question
Recently purchased an "RCBS 4 DIE SET 45 ACP Group B, Part # 18913"
at an auction, I'm new to reloading and can't find any information on these particular dies. I've searched at the RCBS web site but that part # doesn't seem valid. The dies are stamped - ACP.SIZE #1 74, 45 ACP.NC.SEAT#3 74, 45 ACP. CR #4 74, And the fourth die (only marked at top of adjustment knob)
Every where I look RCBS doesn't seem to offer this "4 DIE SET" did I buy antiquated equipment??
Any help in a description of the sequence and purpose of each die would be greatly appreciated!


c3shooter 03-25-2009 03:04 PM

Antiquated? No. Updated by a new model? Possibly. Best shot is to call RCBS, and ask if they have instruction sheet for model you have. Good folks. I broke a de-capping pin on one of my older dies, bought new pins, found they were wrong size, call RCBS. Gave them numbers. Oh, new design- new pins won't work on older dies. So they sent me- FREE- the new decapping pin holder for my dies.

cpttango30 03-25-2009 05:20 PM

ACP.SIZE #1 74 this is your sizer die.

45 ACP.NC.SEAT#3 74 this is your seater die. Look inside to see what kind of bullet it is set up for.

45 ACP. CR #4 74 This is a crimp die.

RCBS ACP 45 not sure on this one. can you take some pictures of it and then take it apart and take pictures of it. Might be able to help you some more if I can see it.

robocop10mm 03-25-2009 06:08 PM

Expander die? 4 die sets usually are 1- Size/de-cap, 2- Expand (flare), 3- seater, 4- taper crimp.

cpttango30 03-25-2009 06:43 PM

Robo I think you got it. and the NC on the seater die mean No Crimp. That is why you have the crimp die. might be an easier set to use on a single stage or a turret but won't work on a lee or a dillon or hornady progressive. unless you get the king of the hill dillon 1050 but who can afford that monster at $1400.

SlamFire 03-25-2009 08:21 PM

Flare or belling die would have a threaded whatever on the top, and looking inside there's a round-nosed rod which expands the mouth of the brass for seating the bullets.

Belling brass is hard on the mouth, but necessary. Go slow, and sneak up on the belling until you have "just enough" to start the bullet base in the mouth. Too little shaves the bullet. Too much splits the case mouth.

45 ACP headspaces on the mouth. Taper crimp needs to be spot-on spec. Sneak up on this too, and go slow . . . Too tight and the case won't headspace. Too loose, and it won't feed, bullet seating slips into the case

N2Abyss 03-26-2009 01:35 AM

Thanks guys, I'll call RCBS for instructions!
This info got me straightened out, being a newbe, I thought I should ...
Step 1: "de-prime" , but now after reading your posts and looking the dies over I see I would flaring before sizing! so... looks like the de-prime and flare die is the die listed only on the knurled knob as "RCBS 45 ACP" actually step #2.

So with the info you guy's have provided and sorting through the dies, should go like this: Step #1 Die #1 Sizer, Step #2 Die (RCBS 45 ACP) De-prime/Flare,
Step #3 Die #3 Seat, Step #4 Die #4 Crimp.

Thanks again for all the help!

cpttango30 03-26-2009 02:34 AM


Step #1 Sizing depriming.

Step#2 belling case mouth.

Step#3 Seating bullet

Step#4 Crimp.

Step #5 shoot.

c3shooter 03-26-2009 10:51 AM

Ummmmm.... Cpt, should there no be a step or two in the middle of your list, called PRIMING and CHARGING (with powder)?

Just ragging ya.

To original poster- get the instructions from RCBS- AND- if you don't already have it- get a copy of The ABCs of Reloading. Available in paperback.

cpttango30 03-26-2009 11:19 AM

I was just going threw the steps involved with the case itself.

I have three steps in mine.

1 put brass in machine

2 put bullets in machine

3 pull handle

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