5.56 shoulder back too far?

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Hey all,
After setting up the die to spec, I sized/primed some LC 5.56 brass in order to have it set up for easy completion down the line. I decided to re-measure the brass with my RCBS precision mic, and somehow the headspace is around -.005 to -0.007 or so. (the mic dials back to 45-43 past zero). With this being loaded for an AR, is this still ok to use, or have I bumped it back too far? And if I have bumped it back too far, what are my options?

I *did* check some of the more extreme ones in a wilson case gauge and they appeared to be within the bottom threshold, but wanted to make sure I'm still ok.

Thanks!
 
Interested in this too... I bought some Speer once fired brass and set the die to touch the shell plate (as the instructions say to), and resized a bunch of it. When I checked the brass in my Dillon go/no-go guage, most are just about flush with the no-go line, and some are definitely a few thou past it.
 
All of the shoulder mics have one huge failing, no calibration. All of these are comparative devices. Find someone with headspace gages and measure those. If your mic is off, remember the discrepancy.
As to setting dies- I'm pretty sure they all say the same thing. Set to the shellholder. This is incorrect except for true straight wall cases. All others to include .30 Carbine need to be set by using your firearm. About a year ago, an acquaintance gave me some 6MM brass that he had acquired from someplace and wanted me to finish reloading them. Someone had sized and trimmed them. When I checked them on my Wilson case gage, they were .035" under min. on the shoulder location. That can only occur when you set dies per manufacturer's instructions.
 
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Hey all,
After setting up the die to spec, I sized/primed some LC 5.56 brass in order to have it set up for easy completion down the line. I decided to re-measure the brass with my RCBS precision mic, and somehow the headspace is around -.005 to -0.007 or so. (the mic dials back to 45-43 past zero). With this being loaded for an AR, is this still ok to use, or have I bumped it back too far? And if I have bumped it back too far, what are my options?

I *did* check some of the more extreme ones in a wilson case gauge and they appeared to be within the bottom threshold, but wanted to make sure I'm still ok.

Thanks!

If they pass the case gauge you ~should~ be fine assuming everything else is in spec.

How are you measuring your headspace? Every chamber is a bit different - generally I take a few cases fired from the chamber in question (with the same headstamp as what I'm going to be loading,) measure them to make sure they're all pretty much the same, subtract about 2 or 3 thou, then play with the sizing die until I hit the resulting number. In the rifles I use for service rifle competition (tight chambers) pushing back .002" usually puts me right at the maximum on a case gauge.

If pushing back .002 puts you at the max, .009 would put you at the min. Your .005 - .007 range should be fine, though you're probably working the brass more than you need to. The fact that they pass the case gauge supports that conclusion.

FYI, the spec for .223 cartridge headspace is 1.4666" - .007" (Note that's not +/-. 1.4666" is both the max and preferred length but you can go as much as .007" past that and technically still be in spec.) I usually just measure it with a mic with one of those Hornady head space bushings clamped on. Seems more precise to me, and a whole set of headspace bushings is cheaper than one Mo's gauge.
 
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Interested in this too... I bought some Speer once fired brass and set the die to touch the shell plate (as the instructions say to), and resized a bunch of it. When I checked the brass in my Dillon go/no-go guage, most are just about flush with the no-go line, and some are definitely a few thou past it.

i did this and found out that just a slight turn more was needed the hard way. loaded some 223 and they would not chamber. i got wilson case gauges and could see the shoulder was a hair to high. i now have case gauges for the 3 rounds i load.
 
If i set my hornady dies in my hornady single stage per instructions it set the shoulder back .002 below the 0 setting on my RCBS precision mike. I was setting my dies to work the brass far more than needed.
I only shoot reloads in one AR. I set my dies to set back that brass .003 using the precision mic.
Since then my brass is not as sooty and my accuracy improved.
It did take a little while to get used to using the rcbs. I have also noticed less case stretch with the dies adjusted for less setback. along with no more stuck cases! so far.
 
All of the shoulder mics have one huge failing, no calibration. The RCBS one, and maybe others, is made of plastic. All of these are comparative devices. Find someone with headspace gages and measure those. If your mic is off, remember the discrepancy.

You may be thinking of a different one, mine are made of metal. It is this one:
http://www.midwayusa.com/product/477756/rcbs-precision-mic-223-remington

If they pass the case gauge you ~should~ be fine assuming everything else is in spec.

How are you measuring your headspace? Every chamber is a bit different - generally I take a few cases fired from the chamber in question (with the same headstamp as what I'm going to be loading,) measure them to make sure they're all pretty much the same, subtract about 2 or 3 thou, then play with the sizing die until I hit the resulting number. In the rifles I use for service rifle competition (tight chambers) pushing back .002" usually puts me right at the maximum on a case gauge.

If pushing back .002 puts you at the max, .009 would put you at the min. Your .005 - .007 range should be fine, though you're probably working the brass more than you need to. The fact that they pass the case gauge supports that conclusion.

FYI, the spec for .223 cartridge headspace is 1.4666" - .007" (Note that's not +/-. 1.4666" is both the max and preferred length but you can go as much as .007" past that and technically still be in spec.) I usually just measure it with a mic with one of those Hornady head space bushings clamped on. Seems more precise to me, and a whole set of headspace bushings is cheaper than one Mo's gauge.

I was just measuring the headspacing of the sized brass. I'm unsure what the starting headspace was, my goal was to get them back to spec (zero on the rcbs mic). I foolishly ended up getting the ones ran through my rifle mixed in with another rifle's, so I will have to get to the range to run more through and measure them (unless I can find my sticky note where I jotted this info down 6 months ago.. ).
IIRC the headspace was around .003, so I could be looking at up to a +.010 difference when all is said and done.
 
I was just measuring the headspacing of the sized brass. I'm unsure what the starting headspace was, my goal was to get them back to spec (zero on the rcbs mic). I foolishly ended up getting the ones ran through my rifle mixed in with another rifle's, so I will have to get to the range to run more through and measure them (unless I can find my sticky note where I jotted this info down 6 months ago.. ).
IIRC the headspace was around .003, so I could be looking at up to a +.010 difference when all is said and done.

Ahh, I see. Still if you're passing the case gauge you're in spec - I would just shoot them this time and maybe back the die off a touch before you resize them next time.
 
Are you reloading for one rifle or multiple ? If only one you should use the rcbs tool to just set the shoulder back just enough, I measured 10 fired cases from my AR then set up my die to only push the shoulder back .003. This is what the precision mic is for right? I dont bother with the AOL cartridge tool that came with it. I load my 223 to max length that will still run in my magazine.
 
Are you reloading for one rifle or multiple ? If only one you should use the rcbs tool to just set the shoulder back just enough, I measured 10 fired cases from my AR then set up my die to only push the shoulder back .003. This is what the precision mic is for right? I dont bother with the AOL cartridge tool that came with it. I load my 223 to max length that will still run in my magazine.

What if they are once fired and shoulder is already short by .003 and your bottoming out your sizing die and the shoulder is not reaching the die?
 
Are you reloading for one rifle or multiple ? If only one you should use the rcbs tool to just set the shoulder back just enough, I measured 10 fired cases from my AR then set up my die to only push the shoulder back .003. This is what the precision mic is for right? I dont bother with the AOL cartridge tool that came with it. I load my 223 to max length that will still run in my magazine.
Multiple rifles, which is why I was aiming for spec (-0- on the mic).
 
What if they are once fired and shoulder is already short by .003 and your bottoming out your sizing die and the shoulder is not reaching the die?

That would be pretty weird. Even with tight match chambers my brass comes out around .001" over SAAMI. Is that actually happening to you or is it a hypothetical question?
 
All of the shoulder mics have one huge failing, no calibration. The RCBS one, and maybe others, is made of plastic.

The RCBS Precision Mic is both calibrated and metal. (The accuracy of the calibration can be debated however).

To the OP:

The "0" on the Precision Mic is the chamber headspace minimum, which for .223 is 1.4636". The minimum cartridge headspace length 0 for .223 is 1.4596" (1.4666" -0.0070").
 
Multiple rifles, which is why I was aiming for spec (-0- on the mic).
For my multiple rifle loads I set me lee die set up so it sizes my brass to pass in the Wilson case gauge... I have not compared the 2 different loadingsxwith the rcbs mic.... I don't have any OCD so my plinking ammo is loaded with various cases cheapest bullets and powder. Runs great for blasting and new shooters.
 
The RCBS Precision Mic is both calibrated and metal. (The accuracy of the calibration can be debated however).

To the OP:

The "0" on the Precision Mic is the chamber headspace minimum, which for .223 is 1.4636". The minimum cartridge headspace length 0 for .223 is 1.4596" (1.4666" -0.0070").
As always, thanks for the input.
Measuring them with the hornady headspace kit, most of them measure 1.4555-1.4560. Checking them in the Wilson case gauge, they look right even with the minimum line.

Safe to shoot, or chunk 'em, or can they be re-sized and stretched out (I'm pretty sure the latter can't be done).
 
I was just measuring the headspacing of the sized brass. I'm unsure what the starting headspace was, my goal was to get them back to spec (zero on the rcbs mic). I foolishly ended up getting the ones ran through my rifle mixed in with another rifle's, so I will have to get to the range to run more through and measure them (unless I can find my sticky note where I jotted this info down 6 months ago.. ).
IIRC the headspace was around .003, so I could be looking at up to a +.010 difference when all is said and done.


Update: Ran a couple mags of factory rounds through rifle (did not have time to make reloads). Looks like all the brass is now measuring +.001 on the rcbs mic.
 
As always, thanks for the input.
Measuring them with the hornady headspace kit, most of them measure 1.4555-1.4560. Checking them in the Wilson case gauge, they look right even with the minimum line.

I just bought some new LC 13 brass.
I checked mine with a Hornady head space bushing.
I too end up at 1.4555 before sizing, or shooting. They fit perfect in my Dillon Headspace/case length gauge. Brass OAL is perfect, not trimmed
I am now wondering if they were fired, resized and sent out as new. Or are some cases made different?
They look new though.
Thanks, Mike
 
This is a good book. I have attached a few pages.
That's the picture I have been looking for. Thanks! None of the ones I have found have the datum line. Does it also include tolerance info in the book? I might have to pick one of those up.

Is .007" less than the max length true for all cartridges? I have been bumping it just a little to fit my guns, but obviously commercial ammo is sized differently- to work in all guns.
 
Wow I didn't even think that would be an option. Thanks for the link. Would it be worth adding the saami page to the list of links in sticky section? I'm sure I'm not the only one who has had that question before.
 
Wow I didn't even think that would be an option. Thanks for the link. Would it be worth adding the saami page to the list of links in sticky section? I'm sure I'm not the only one who has had that question before.

Download it and save it.

It was available for a while, then not available (at least not for free), and apparently it's available again.
 
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