Sizing *after* trimming?

[elenius]

I noted with some surprise that the Hornady reloading manual lists the trimming step before the sizing step, in their rifle reloading instructions.

My Lyman has it the other way, with sizing first, then trimming, then everything else. I thought this second way was the way to do it, because sizing could change the COL. Is this not the case? Is it ok to trim first? This would simplify the process for me when loading on my 550, because I could do all the prep work first, including trimming, and then just do the four stations in one go.

[D.Hayden]

Daniel.. size first then trim.

I do all the prep work first..

Lube

Size

Trim

Tumble

Then, just put a nexk sizer die in station one and load them up. The neck sizer will expand the case mouth, and get rid of any tumbling media in the primer hole.

[elenius]

Daniel.. size first then trim.

I do all the prep work first..

Lube

Size

Trim

Tumble

Then, just put a nexk sizer die in station one and load them up. The neck sizer will expand the case mouth, and get rid of any tumbling media in the primer hole.

So you use both a full-length sizer and a neck sizer? Why?

[D.Hayden]

Neck sizer only on the load step..

Full length to size before trimming.

These are different tool heads. I prep all the brass first, then load whenever I want, with processed brass.

The Dillon trimmer, doesn't expand the case mouth, you still need to do that before loading.

That make more sense?

On a 550.. I'd have

1 toolhead: Full Sizer, Trimmer

another: neck sizer, powder measure, seater, crimper

[elenius]

Neck sizer only on the load step..

Full length to size before trimming.

These are different tool heads. I prep all the brass first, then load whenever I want, with processed brass.

The Dillon trimmer, doesn't expand the case mouth, you still need to do that before loading.

That make more sense?

On a 550.. I'd have

1 toolhead: Full Sizer, Trimmer

another: neck sizer, powder measure, seater, crimper

Do you mean "the Dillon full length sizing die doesn't expand the case mouth"? Hmm, mine has a "carbide expander ball". I thought that was for neck sizing. Dillon don't even make a neck size die as far as I can tell, although they do sell a Redding neck sizer... I'm confused.

[D.Hayden]

How are you trimming the cases?

The Dillon Trimmer.. sizes but doesn't have the expander...

How about this..

Trim the cases after full lenght sizing...

Before you load, make sure the case mouth has been expanded...

Edited August 8, 2007 by BerKim

[elenius]

How are you trimming the cases?

That's one of the things I'm trying to figure out

The Dillon Trimmer.. sizes but doesn't have the expander...

Oh, I see. Are you talking about the powered thing that you're supposed to clamp a vacuum on to?

(i.e. the Rapid Trim 1200B, http://www.dillonprecision.com/#/content/p...0B_Case_Trimmer )

I was going to get a separate trimmer (probably a hand-cranked one, maybe the Lyman).

Edited August 8, 2007 by elenius

[moredes]

Yup, size first, then trim. I only trim once. I use an RCBS X-die, and that has eliminated trimming--then again, I'm not benchresting, I'm shooting semi-autos.

[kurtm]

I use the Dillon trimmer and trim first. It is a sizing die after all and if you trim 8 thouh less than max, the little bit the case grows after the expander ball does it's thing will still be 5 though under the max case length. Just make sure you aren't undersizing the case when you set up your Dillon trim die. I like to take a fired case from my tightest chamber and smoke the shoulder and neck and set the trim die so that it ALMOST goes all the way down the neck stopping just befor it touches the shoulder. KURTM

[David Sinko]

I use the cheapo Lee setup and I have to trim before I resize. The gauge generally won't fit into the case mouth if the case is resized first. The problem with this is I need to deprime the cases first without resizing them. It is very slow, but I am a cheapskate and it does work. The one exception is the .22 Hornet trimmer which will fit into .223 brass after it has been resized, but then will not trim to a uniform length.

When I am really bored I expand and then trim some .357 Sig brass and then shoot it in my .40 S&W. People soon realize that I am not quite right and stop shagging my brass.

Dave Sinko

[aedavis]

For my AR (223), I used to size first, then trim. I have since changed over to an Xdie for this caliber and now trim first, then size.

Allan

[BPiatt]

Here's what I've found works good for volume .223 case prep for use in my AR's:

Luckily for me, I have a large supply of once fired Federal .223 that I get from my police job. I tumble clean them, spread them on a McDonald's tray and spray them with Hornady One Step case lube. I pour them in the case feeder for my Dillon 1050 that has been set up like this.

On my Dillon 1050, I have the first station with a full length sizer and decapper but adjusted so it's only partially sizing the case. The decapper is removing the primer and the case is partially sized. The amount of sizing doesn't matter and I'll explain later. Station two is doing the primer pocket swaging, even if it doesn't need it, this station will check that the primer has been removed. The only other station doing anything is directly opposite of station #1 with the sizer. There I've set up the Dillon FL sizer/power trimmer. Here is where I do the final sizing adjustment. I adjust the size die until they measure "zero" on a RCBS case gauge. OAL is set at whatever you want. I take my measurement right out of a reloading manual. When the cases are ejected, they are sized to factory specs ready for loading. Depending on the amount trimmed and how sharp your trimmer is, you may want to de-burr the case mouth. I do that by chucking a deburr tool in a drill press, grab a handful of cases and just touch the spinning deburr tool to the case mouth. I do not set the case down and raise and lower the drill press. After this, I retumble them to remove the case lube and the trimming debris that may be stuck to them. When I load, also on the 1050, I have the size die coming down on the neck about 1/2 way and the decapping pin/inside neck expander working. The neck size will insure nothing got dented up during tumbling, the decapper will remove any tumbling media from the flash hole, and the expander will adjust the neck for proper bullet tension.

NOTE: It is important to set up two size dies on the 1050. When I first tried one size die, the cases were measuring +/- .003 or .004 after trimming. Now I'm not sure if it's because the cases came from 6 different guns or the reloading machine had some tolerance issues with only one die doing any work on the down stroke. Either way, having two sizing dies AT OPPOSITE sides of the machine brought the sizing diffences down to +/- .001. Pretty much the same tolorances if you were doing it on a single stage press.

Edited November 4, 2007 by BPiatt

[DougCarden]

Bruce, thanks for that info! I am getting ready to load a buttload of .223 on my 1050 and I will be trying your set up!

Thanks,

DougC

[hiropro]

Bruce, thanks for that info! I am getting ready to load a buttload of .223 on my 1050 and I will be trying your set up!

Thanks,

DougC

I need a 1050 this 650 does not offer the pocket swaging and Now i have a large source of LC brass once fired.

damn there goes another grand.

[RePete]

I trim after sizing.

I may check the size before though.

[RevolverJockey]

I use the cheapo Lee setup and I have to trim before I resize. The gauge generally won't fit into the case mouth if the case is resized first.

Dave,

that seems a bit odd to me. What kind of size die are you using? I have a lot of different combination starting with Hornady, RCBS SB, Lee and Redding sizers and they all seem to make it easier to use the Lee pilot/trimmer.

Lee