setting die on press and measuring

attila787 · August 9, 2009, 01:19 AM

How do you now if the die setting/measure is correct specifically the resizing depriming die when screwed on the press?

I have successfully deprimed and re-sized a few of my .308 brass, but before I keep going I want to make sure I'm not missing something. I found that there is some play with the length/measuring that still gives the same results.

Maybe I'm being to picky, but never to careful.

Shoney · August 9, 2009, 02:03 AM

What brand of dies do you have?

Did they come with instructions?

Randy 1911 · August 9, 2009, 05:19 AM

The way I have always done rifle dies on the sizer die I just screw it in until it contacts the shellholder/shellplate and then back it out 1/4 turn. That should give you full lenth sizing. If your dies came with instructions, go by what they say.

wncchester · August 9, 2009, 08:18 AM

"The way I have always done rifle dies on the sizer die I just screw it in until it contacts the shellholder/shellplate and then back it out 1/4 turn."

Not really correct. No matter the die brand, SAAMI specs for both die and shell holder is aimed at trying to produce a "full length" sized case when the die and shell holder are just barely contacting when the press is under full pressure with a case in the die. All presses have some amount of spring so it generally takes another bit of turning IN/DOWN to accomplish that. Turning a 7/8x14 die a quarter turn OUT/UP means you are sizing about .018" LESS than SAAMI specifications.

The normal SAAMI spec for minimum to maximum headspace is only some .008" or so, or about half of that quarter turn. Meaning a quarter-turn is a MASSIVE sizing change, either way, for a case.

"Correct" sizing for a reloader is ideally done when the shoulders are moved back enough to allow easy chambering, and no more, for his own rifle regardless of any shell holder to die contact. Sizing correctly makes for easy shooting ammo that won't stretch too much, and that means longer safe case life.

**Unclenick** · August 9, 2009, 08:46 AM

Wncchester is correct about standard die instructions. A quarter turn back on the 7/8"-14 tpi threads would be 0.018", or over twice the SAAMI chamber tolerance. Cases usually have two or three thousandths overlap into minimum chamber dimensions because guns can size them a bit on chambering, but that only raises the tolerance to 0.011". What is desired in the setup is contact between the end of the die and the shellholder that is hard enough that you can see no crack of light between the shell holder and die when you have an actual case lubed and pressed up into it. The extra pressure applied to compensate for press stretching then also compensates for one case being a little harder to size than another due to brass thickness variance or work hardening.

You can see correct sizing die set up demonstrated on Lee's help video. The only difference to the video instruction will be if you have an iron or steel press instead of one of Lee's aluminum presses. Aluminum frame presses require a larger amount of extra turn-in after making die contact. Aluminum strain is about 3 times longer in response to a given stress than steel or iron. Also, with Lee dies is the rubber O-ring in the locking nut that secures the die position may be tightened by hand alone, where most brands have a set screw to tighten.

If your particular gun has a generous chamber, then you have a situation where you don't really need full resizing, but still want to minimize variance in sizing by having some extra press pressure at the die/shellholder interface. To handle that, Redding has their Competition Shellholder sets which have increased thickness in steps of 0.002" so you can pick you sizing length up to 0.010" over normal resizing length. If, on the other hand, you happen to get a tight chamber or an auto-loader that is extra feed picky and needs extra sizing on cases, what are called small base sizing dies are available from RCBS and others that are 0.002" shorter than normal and force the case shoulder down that much further.

Uncle Billy · August 9, 2009, 09:15 AM

The way I was taught to do it is to turn the resize/deprime die into the press until it contacts the ram at the top of its travel, as in the video linked in Unclenick's post. Then back the ram off a bit and turn the die further into the press a little. It's at the proper depth in the press when the ram handle can go over center with only a little extra push on the handle, but won't go all the way over center without the push. With the ram over center on the die, which preloads it in the press, the lock ring is tightened firmly. Doing it this way takes out any slop in the die's fit in the press and compensates for any stretch. That little bit of extra effort necessary at the top of the ram's travel should be evident with each case which is an indication you're resizing the case over all the length possible. Or so I was told.

attila787 · August 9, 2009, 09:40 AM

I'm using Lee dies and that video really helps.

Another question does the bushing they sale for the Lee dies really worth it?

jepp2 · August 9, 2009, 10:39 AM

Just to add to what the others have said.

You seem "new" to rifle reloading. You do know that you don't have to full length resize each time, provided you are firing the same brass in the same rifle and it helps if it is a bolt action (not a semi auto).

If you are wanting the just neck size the brass (it will be slightly more accurate and last much longer and requiring less trimming), back the die off some and watch the neck to see the amount of resizing you need for sufficient neck tension for bullet retention.

If you are full sizing, or even neck sizing, make sure you are testing the resized brass in your rifle chamber to check before you proceed with loading. See if the action will close without excessive force.

I load for various AR's, and found the use of a Lyman cartridge gauge to be very helpful in adjusting my sizing dies. I have several, and there is CONSIDERABLE difference in how I need to adjust them relative to the shell holder to achieve the same amount of shoulder set back. Some are barely touching, some have considerable contact (cam over of the press). And always with the same shell holder.

**Unclenick** · August 9, 2009, 12:56 PM

The bushings let you set the dies up, then pop them in and out without setting them up all over again each time. I consider that worthwhile. If you load a lot on a single stage, it will speed things up. If you load very infrequently, it will keep you from having to remember how you set them up last time? Whether the cost is justified or not is an individual question as to how much your time is worth? One situation in which it would not be so helpful is if you are rotating loading the same chambering on the same set of dies through loads for several guns that each needed slightly different settings. Then you'd have to set up separately each time anyway.

GP100man · August 9, 2009, 12:58 PM

i set my die to resize just enuff to close the bolt reliably.
revolver rounds get the full monty.

jepp2 · August 9, 2009, 06:55 PM

I certainly wasn't being critical of the Redding shell holders. I was just giving a reference that die set up varies considerably, and no "1/4 turn past first contact" type input will give the right die set up. It all depends on the die or shell holder height involved.

August 9, 2009, 01:19 AM	#1
attila787 Senior Member Join Date: May 7, 2007 Posts: 259	setting die on press and measuring How do you now if the die setting/measure is correct specifically the resizing depriming die when screwed on the press? I have successfully deprimed and re-sized a few of my .308 brass, but before I keep going I want to make sure I'm not missing something. I found that there is some play with the length/measuring that still gives the same results. Maybe I'm being to picky, but never to careful.

August 9, 2009, 02:03 AM	#2
Shoney Senior Member Join Date: February 21, 2002 Location: Transplanted from Montana Posts: 2,311	What brand of dies do you have? Did they come with instructions? __________________ I pledge allegiance to the Flag - - -, and to the Republic for which it stands….Our Forefathers were brilliant for giving us a Republic, not a democracy! Do you know the difference??? and WHY?http://www.wallbuilders.com/LIBissue...les.asp?id=111

August 9, 2009, 05:19 AM	#3
Randy 1911 Senior Member Join Date: May 7, 2009 Location: Western Arkansas Posts: 273	The way I have always done rifle dies on the sizer die I just screw it in until it contacts the shellholder/shellplate and then back it out 1/4 turn. That should give you full lenth sizing. If your dies came with instructions, go by what they say. __________________ Been Reloading 27 Years NRA Member Member Old Fort Gun Club www.ofgc.org

August 9, 2009, 08:18 AM	#4
wncchester Senior Member Join Date: December 1, 2002 Posts: 2,832	"The way I have always done rifle dies on the sizer die I just screw it in until it contacts the shellholder/shellplate and then back it out 1/4 turn." Not really correct. No matter the die brand, SAAMI specs for both die and shell holder is aimed at trying to produce a "full length" sized case when the die and shell holder are just barely contacting when the press is under full pressure with a case in the die. All presses have some amount of spring so it generally takes another bit of turning IN/DOWN to accomplish that. Turning a 7/8x14 die a quarter turn OUT/UP means you are sizing about .018" LESS than SAAMI specifications. The normal SAAMI spec for minimum to maximum headspace is only some .008" or so, or about half of that quarter turn. Meaning a quarter-turn is a MASSIVE sizing change, either way, for a case. "Correct" sizing for a reloader is ideally done when the shoulders are moved back enough to allow easy chambering, and no more, for his own rifle regardless of any shell holder to die contact. Sizing correctly makes for easy shooting ammo that won't stretch too much, and that means longer safe case life. Last edited by wncchester; August 9, 2009 at 08:25 AM.

August 9, 2009, 08:46 AM	#5
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Wncchester is correct about standard die instructions. A quarter turn back on the 7/8"-14 tpi threads would be 0.018", or over twice the SAAMI chamber tolerance. Cases usually have two or three thousandths overlap into minimum chamber dimensions because guns can size them a bit on chambering, but that only raises the tolerance to 0.011". What is desired in the setup is contact between the end of the die and the shellholder that is hard enough that you can see no crack of light between the shell holder and die when you have an actual case lubed and pressed up into it. The extra pressure applied to compensate for press stretching then also compensates for one case being a little harder to size than another due to brass thickness variance or work hardening. You can see correct sizing die set up demonstrated on Lee's help video. The only difference to the video instruction will be if you have an iron or steel press instead of one of Lee's aluminum presses. Aluminum frame presses require a larger amount of extra turn-in after making die contact. Aluminum strain is about 3 times longer in response to a given stress than steel or iron. Also, with Lee dies is the rubber O-ring in the locking nut that secures the die position may be tightened by hand alone, where most brands have a set screw to tighten. If your particular gun has a generous chamber, then you have a situation where you don't really need full resizing, but still want to minimize variance in sizing by having some extra press pressure at the die/shellholder interface. To handle that, Redding has their Competition Shellholder sets which have increased thickness in steps of 0.002" so you can pick you sizing length up to 0.010" over normal resizing length. If, on the other hand, you happen to get a tight chamber or an auto-loader that is extra feed picky and needs extra sizing on cases, what are called small base sizing dies are available from RCBS and others that are 0.002" shorter than normal and force the case shoulder down that much further. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; August 9, 2009 at 09:00 AM. Reason: added link

August 9, 2009, 09:15 AM	#6
Uncle Billy Senior Member Join Date: June 10, 2009 Location: Small city in New York Posts: 482	The way I was taught to do it is to turn the resize/deprime die into the press until it contacts the ram at the top of its travel, as in the video linked in Unclenick's post. Then back the ram off a bit and turn the die further into the press a little. It's at the proper depth in the press when the ram handle can go over center with only a little extra push on the handle, but won't go all the way over center without the push. With the ram over center on the die, which preloads it in the press, the lock ring is tightened firmly. Doing it this way takes out any slop in the die's fit in the press and compensates for any stretch. That little bit of extra effort necessary at the top of the ram's travel should be evident with each case which is an indication you're resizing the case over all the length possible. Or so I was told. __________________ Despite the cost of living, have you noticed how popular it remains?

August 9, 2009, 09:40 AM	#7
attila787 Senior Member Join Date: May 7, 2007 Posts: 259	I'm using Lee dies and that video really helps. Another question does the bushing they sale for the Lee dies really worth it?

August 9, 2009, 10:39 AM	#8
jepp2 Senior Member Join Date: December 24, 2008 Location: Loveland, CO Posts: 1,476	Just to add to what the others have said. You seem "new" to rifle reloading. You do know that you don't have to full length resize each time, provided you are firing the same brass in the same rifle and it helps if it is a bolt action (not a semi auto). If you are wanting the just neck size the brass (it will be slightly more accurate and last much longer and requiring less trimming), back the die off some and watch the neck to see the amount of resizing you need for sufficient neck tension for bullet retention. If you are full sizing, or even neck sizing, make sure you are testing the resized brass in your rifle chamber to check before you proceed with loading. See if the action will close without excessive force. I load for various AR's, and found the use of a Lyman cartridge gauge to be very helpful in adjusting my sizing dies. I have several, and there is CONSIDERABLE difference in how I need to adjust them relative to the shell holder to achieve the same amount of shoulder set back. Some are barely touching, some have considerable contact (cam over of the press). And always with the same shell holder.

August 9, 2009, 12:56 PM	#9
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	The bushings let you set the dies up, then pop them in and out without setting them up all over again each time. I consider that worthwhile. If you load a lot on a single stage, it will speed things up. If you load very infrequently, it will keep you from having to remember how you set them up last time? Whether the cost is justified or not is an individual question as to how much your time is worth? One situation in which it would not be so helpful is if you are rotating loading the same chambering on the same set of dies through loads for several guns that each needed slightly different settings. Then you'd have to set up separately each time anyway. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

August 9, 2009, 12:58 PM	#10
GP100man Senior Member Join Date: August 1, 2007 Location: Tabor City , NC. Posts: 1,969	i set my die to resize just enuff to close the bolt reliably. revolver rounds get the full monty. __________________ GP100man

August 9, 2009, 06:55 PM	#11
jepp2 Senior Member Join Date: December 24, 2008 Location: Loveland, CO Posts: 1,476	I certainly wasn't being critical of the Redding shell holders. I was just giving a reference that die set up varies considerably, and no "1/4 turn past first contact" type input will give the right die set up. It all depends on the die or shell holder height involved.