Fired Brass Can't be Re-Sized

Okay, so a couple of questions:

1. What is "spec"? I just spent some time at www.saami.org looking at drawings. SAAMI list MAX Cartridge and MIN Chamber drawings. There is no MAX Chamber dimensions listed. Also, being that SAAMI spec is voluntary manufacturing recommendations, is anyone really held to SAAMI spec? The fired casings do measure way over MAX Cartridge spec at the base and shoulder of the case but, that is before resizing.

2. How much more information is a chamber casting going to give me over the fired case? We all know that the brass casing retracts in size after firing. Otherwise it would not extract and eject. If SAAMI list no MAX Chamber spec, how can I point the finger at the manufacturer for being "out of spec".

What am I missing here?

Still in the cue and on hold with the manufacturer.
If you read the saami print-- down near the bottom right under the chamber dimensions--- there is a notation that says " CHAMBER" and it is underlined--- it says "unless otherwise noted all dia +.002" (.050mm)" and then it says "length tol. +.015" (0.38mm)" so you have a +.002" diameter and +.015" length tolerances over what the drawing specifications state.

Is it a 308W chamber, or 7.62x51 nato? I dont know where to find Nato spec drawings, but I'm pretty sure that the nato chambers are looser


so your chamber has a max diameter of .002" larger than the chamber print (so .4734" at base and .4571" at shoulder--diameter) and a max length of +.015"
you will also note that the "datum line" measurement does have a min and max-- this would be 1.630" min and 1.604" max --these would be your head space measurements


just found that nato max is 1.6455 for headspace, not sure on diameter yet


you said your brass was oversize--did I miss where you said if it was over length or over diameter?

as far as the rifle manufacture, I hope they stand behind it if the chamber is out of spec, BUT most manufactures will plainly state in the manual that if you shoot reloaded ammo in your rifle it will void the warranty, so you may be opening up a can of worms by telling them you are trying to resize the brass to reload
 
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Seem to recall that Armalite warns that using handloaded ammunition voids their warranty... Was plainly stated in their owners manual. Just mentioning this even though you may not own an Armalite, but their policy could be widely practiced. Before entering a claim, might want to be sure reporting your situation doesn't void the warranty entirely. Might consult your dealer or gunsmith with your findings and ask for their help; so you can use your fired brass in other same chambered rifles.

As far as precision goes, your 5rd group looks excellent; certainly showing promise for even better results.

If the rifle is brand new, work a return with the dealer and only mention the Gold Medal factory loads coming out so oversized. I would sure be distressed, too, if ths happened... Good luck!
 
If you read the saami print-- down near the bottom right under the chamber dimensions--- there is a notation that says " CHAMBER" and it is underlined--- it says "unless otherwise noted all dia +.002" (.050mm)" and then it says "length tol. +.015" (0.38mm)" so you have a +.002" diameter and +.015" length tolerances over what the drawing specifications state.

Is it a 308W chamber, or 7.62x51 nato? I dont know where to find Nato spec drawings, but I'm pretty sure that the nato chambers are looser


so your chamber has a max diameter of .002" larger than the chamber print (so .4734" at base and .4571" at shoulder--diameter) and a max length of +.015"
you will also note that the "datum line" measurement does have a min and max-- this would be 1.630" min and 1.604" max --these would be your head space measurements


you said your brass was oversize--did I miss where you said if it was over length or over diameter?

as far as the rifle manufacture, I hope they stand behind it if the chamber is out of spec, BUT most manufactures will plainly state in the manual that if you shoot reloaded ammo in your rifle it will void the warranty, so you may be opening up a can of worms by telling them you are trying to resize the brass to reload

Thanks. I see what you are talking about. That helps.

It was the diameter that was way out of spec in my opinion. I will measure again when I get home.

Nothing in the manual about using hand loads voiding the warranty.
 
Did you anneal the cases before resizing?You might have to anneal before resizing every time.With an adjustable gas block you can time your action so it does not eject the case before it is ready.The case can grab the chamber and stretch.So your cases are getting work hardened.Just a thought,Huntz
The new brass was annealed. And, I anneal after every firing. Just a good practice for precision neck tension I think.
 
I have sized 7.62 brass coming out of military machine guns, as have many who use Lake City brass, with no problem. Machine guns have sloppy chambers, by design so they go bang again and again when the trigger is pulled yielding sloppy brass. I never had a problem resizing the machine gun brass even with a small base die, my press is a Rockchucker that I have had for over 45 years.

Long story short, my guess is your chamber is out of spec. A very easy cop out on the manufacture's part to say we did not build this for reloaders we built it for warfighters. Kind of an advertising statement and cop out in one sentence, the internet warriors would never "go outside the wire" without a gun that is not "built for the warfighter". It is very easy for a keyboard warrior sitting at home to say what or what they would not "go outside the wire" with.

I was not in the service but I would imagine the non SF folks may not have a lot of say in what they carry as they perform their missions. To support my customers I did spend some time in Iraq, keeping my *** inside the wire and still puckering, in '07 and my appreciation for the troops and the job they are asked to do was greatly elevated by the experiences in Iraq.

Sorry for the rant
 
I Hope the Factory Will provide exact Chamber Specs to you!! They Can Measure all Dimensions of the Chamber reamer and Send the Numbers to you
 
Measuring the reamer will only tell you the minimum possible size of the chamber, with a poor setup the reamer can cut a chamber that is larger than its specs.
 
All good points and suggestions. Thanks.

It is a high dollar gun. I don't know if I am willing to spend more or not. I should not have to.

Still on hold. Going on an hour now.
Welcome.

That was my concern, that it was a high dollar rifle and if the mfg won't stand behind it that screwing in a good barrel on your dime puts you upside down in it. Flip of the coin, if it's what you've been wanting (aside from the obvious problem) and has hard to find specific features then maybe its worth fixing on your dime. If it is fairly generic and easily replaced then it probably is not worth fixing.
 
does anyone have a copy of the STANAG no. 2310 document? I think we may be dealing with a real 7.62x51 nato chamber on his rifle, I know the nato chamber "max length gauge" is longer than the no-go and field gauge for the 308w, But I can't seem to find a set of detailed prints for the chamber drawing and tolerances for the OP

I would think a set of dies would still re-size the cases though
 
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Okay, so a couple of questions:

1. What is "spec"? I just spent some time at www.saami.org looking at drawings. SAAMI list MAX Cartridge and MIN Chamber drawings. There is no MAX Chamber dimensions listed. Also, being that SAAMI spec is voluntary manufacturing recommendations, is anyone really held to SAAMI spec? The fired casings do measure way over MAX Cartridge spec at the base and shoulder of the case but, that is before resizing.

2. How much more information is a chamber casting going to give me over the fired case? We all know that the brass casing retracts in size after firing. Otherwise it would not extract and eject. If SAAMI list no MAX Chamber spec, how can I point the finger at the manufacturer for being "out of spec".

What am I missing here?

Still in the cue and on hold with the manufacturer.
woolecox wrote: 2. How much more information is a chamber casting going to give me over the fired case?
You are going to need all the proof available !! I'm bettin' making a chamber cast will be the first thing the company does once ( if ever) the rifle is in their hands for inspection.
 
So I read the whole thread and didn't see it anywhere...will the fired cases rechamber? If not, it's not the chamber oversized it's extracting too early.
Yes, as far as I can tell the brass does re-chamber after firing. But, how can I be sure that the bolt is closing and rotating all the way on a semi auto?
 

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