New Winchester brass does not properly headspace

[pacobillie]

Wondering if anyone has encountered this?

I make brass for my 9.3X57 rifle from 8X57 Mauser brass.

I initially bought a batch of Metalwerken brass and had no issues, other than a slightly thick neck near the shoulder.

I then tried WW Super (Winchester) brass and had no neck issue. The sizing die setting remained the same. However, the spent primers were protruding after the initial firing, and the case was shiny just above the base, which are indications that the cases are not headspacing properly. After the second load, the primers were OK but flat. After the third load, I experienced case separation above the case head.

I have not had this happen with any of the Metalwerken cases, only with the Winchester.

Is this true of all Winchester 8X57 brass, or did I just buy a batch that is sized slightly short?

 

[Suther]

Is it the brass or your rifle that has bad headspace? From what I've read Those old 9.3x57s are known to have varying chamber dimensions. Have you heard about expanding it larger than necessary and then slowly adjusting the sizing die until your brass just fits in your chamber?

The fact you had a case separation after 3 loads makes me think you are bumping the shoulder too far when sizing them.

 

[pacobillie]

Is it the brass or your rifle that has bad headspace? From what I've read Those old 9.3x57s are known to have varying chamber dimensions. Have you heard about expanding it larger than necessary and then slowly adjusting the sizing die until your brass just fits in your chamber?

The fact you had a case separation after 3 loads makes me think you are bumping the shoulder too far when sizing them.

I have also read that about some of the old Huskys having an overly long chamber. However, if that were the issue, the problem would arise with all brands of brass, not just the Winchester. Further, the issue has arisen in two different rifles: a M46 and a M146.

I have not tried expanding to a larger diameter and then sizing down. I do not have a proper expander to do that. What I am going to try next is to make my next batch from 30-06 brass (the neck will be formed from the shoulder of the original case, after cutting to length), and size them so that I get a quasi crush fit in my chamber.

 

[Suther]

I have also read that about some of the old Huskys having an overly long chamber. However, if that were the issue, the problem would arise with all brands of brass, not just the Winchester. Further, the issue has arisen in two different rifles: a M46 and a M146.

I have not tried expanding to a larger diameter and then sizing down. I do not have a proper expander to do that. What I am going to try next is to make my next batch from 30-06 brass (the neck will be formed from the shoulder of the original case, after cutting to length), and size them so that I get a quasi crush fit in my chamber.

Could the slightly thicker neck on the other brass be the reason it doesn't do what the Wichester brass is doing?

Did the winchester brass come from a white/blue bag, or the newer red/black bags? I hear the newer stuff is pretty crappy, although I haven't used it myself.

 

[pacobillie]

Could the slightly thicker neck on the other brass be the reason it doesn't do what the Wichester brass is doing?

Did the winchester brass come from a white/blue bag, or the newer red/black bags? I hear the newer stuff is pretty crappy, although I haven't used it myself.

Red black bag!

 

[bearhunter]

The pressures you are reaching to fireform your loads isn't high enough.

My suggestion is to use a full load, the same as you use for your usual load and the cartridge should fireform to the proper dimensions.

 

[Potashminer]

Not a lot of experience at this conversion yet, but you describe about perfectly what I had learned here on CGN - have to oversize the neck, then create a false shoulder, and then fire form - can not rely on the original 8x57 to provide appropriate headspace for your 9.3x57. I used the elliptical shaped expander in the Hornady 9.3x57 die to open the 8x57 necks to 9.3, then bought RCBS set #18608 - 44 mag, etc. - that sizer is too big to fit, so have now got Lyman 41 magnum, which seems okay. Then back into that 9.3x57 full length die and a partial turn at a time until the bolt just so closes on that false shoulder. Took a couple back and forth to get it just snug, without too tight or at all loose - then giver 'er with the resize and fire form.

 

[dan belisle]

I made mine for years from 30-06 brass. Procedure was similar to Potash's. - dan

 

[pacobillie]

Not a lot of experience at this conversion yet, but you describe about perfectly what I had learned here on CGN - have to oversize the neck, then create a false shoulder, and then fire form - can not rely on the original 8x57 to provide appropriate headspace for your 9.3x57. I used the elliptical shaped expander in the Hornady 9.3x57 die to open the 8x57 necks to 9.3, then bought RCBS set #18608 - 44 mag, etc. - that sizer is too big to fit, so have now got Lyman 41 magnum, which seems okay. Then back into that 9.3x57 full length die and a partial turn at a time until the bolt just so closes on that false shoulder. Took a couple back and forth to get it just snug, without too tight or at all loose - then giver 'er with the resize and fire form.

I hear you, but I am puzzled, since the head to shoulder dimension on the respective cartridges are as follows, per CIP specs:

8X57: 46.2 mm
9.3X57: 45.85 mm

So, in order to make 9.3x57 from 8X57, you theoretically have to push back the shoulder by 0.35 mm. Yet, these numbers seem to be off since I can easily chamber an 8X57 case in both of my rifles, which appears to validate your theory about excessive headspace.

 

[tiriaq]

You are going to have to prepare the cases to fit your rifle. Do that, and headspace issues are irrelevant.

 

[Potashminer]

Yes - only "story" that makes sense to me is somewhat "sloppy" standards - maybe "varying" standards is better phrasing - in those 9.3x57 chambers. No doubt there are some that are shorter and just a run of the 8x57 brass through a 9.3x57 die and it works. Satisfied myself that the one chamber that I have here is on the "longer" side, so went with the false shoulder process. More fussing, but I know they fit, before even fired the first time. I have no experience with either metalverken or winchester brass - pretty much got my "lifetime supply" of PPU 8x57 brass from TradeEx - not much chance of "wearing them out" in the years that I have left, shooting cast bullet loads...

 

[emerson]

Case head separation on 3rd use. Are you FL resizing each time? One good load should fireform, no? Then neck size, bump the shoulder and trim when it won’t chamber properly anymore?

 

[Dogleg]

Make a false shoulder for first firing. Size minimally after that. Problem solved. Seating bullets into the lands to headspace doesn't usually work. Protruding primers are a sign of low pressure.

 

[pacobillie]

Case head separation on 3rd use.

FL resizing indeed.

 

[pacobillie]

Make a false shoulder for first firing. Size minimally after that. Problem solved. Seating bullets into the lands to headspace doesn't usually work. Protruding primers are a sign of low pressure.

Not sure if a false shoulder would work on a 9.3X57. The shoulder is already minimal.

Those rifles M46 and M146 have a lot of free bore. Seating the bullet into the lands would be almost impossible.

With all due respect, protruding primers are usually a sign of excess headspace. FYI, this was a max load!

 

[Suther]

Not sure if a false shoulder would work on a 9.3X57. The shoulder is already minimal.

Those rifles M46 and M146 have a lot of free bore. Seating the bullet into the lands would be almost impossible.

With all due respect, protruding primers are usually a sign of excess headspace. FYI, this was a max load!

Yeah. I'm sure Dogleg has no idea what he's talking about.

Max load based on who's data? Do you have a chronograph to check velocity?

 

[Potashminer]

Not sure if a false shoulder would work on a 9.3X57. The shoulder is already minimal.

...

You are correct that it does not look like much shoulder compared to 30-06 or similar, but I can confirm that it is definitely enough shoulder to position the case in the chamber, tightly. When I say that I expand the neck, I mean the cartridge becomes pretty much a straight wall case - not just a smidgeon bigger than the 9.3 neck. If I have my full length die a bit too long, can not close the bolt on that case - so is enough there to "stop" the bolt - did not try to force it closed, but not intending to "re-size" in the chamber - very noticeable on closing when it gets correct. Looking close at those re-formed ones, I don't think the shoulder is fully "filled out" compared to a once fired one.

My first tool for expanding necks I made on the lathe - sort of copied Internet idea - an "insert" for a Universal Lee taper tool - has a 0.390" nose with taper on the end - goes into the 9.3 neck easily and gets brass opened up nicely. Have nothing here to grind more taper into that expander in the 44 Mag set, so followed Internet advice (Darryl S. on another website forum and Why Not? on this website) decided to buy the .41 mag size

The expander in the .41 Mag die set - Lyman #7601202 - is an M die thing - the nose part measures about .405". Might need to first "bump" with a Lee taper expander to let that .405" thing start in there, but opens the 8x57 case pretty much straight - then start again with the 9.3 die to create and position the false shoulder - on the brass can no longer clearly see where the original 8x57 shoulder was compared to the new formed 9.3x57, that just so let the bolt close.

First two attempts with that 44 Mag sizer did not go well - had run 8x57 cases through the 9.3 expander, then bumped with the Lee Universal taper crimp, then tried ramming the 44 sizer through. Not so good:




Made up my own tool for that Lee Universal taper tool - saw this on Internet somewheres - not my "invention" - bottom one in picture:




Still managed to mess up by not getting depth set properly - rolled over the mouth edge - right case. But left one is what I was after - ready to go back into 9.3x57 full length die to create a false shoulder.

 

[pacobillie]

Max load based on who's data? Do you have a chronograph to check velocity?

Load is 44.8 gr of H4895 behind a 285 gr PRVI bullet. Clocked at 2125 fps on my Pro-Chrono. 24 inch barrel.

 

[Potashminer]

If your fired cases have protruding primers when you extract them, that can only happen if there was "space" available between the bolt face and the shoulder of the chamber. That protruding primer took up that extra space. So, if nothing else, the protruding primer says that your cases were a bit short, between the closed bolt face and the chamber shoulder. In a normal firing sequence, there will be a couple thou or so of space - primer will back out to bolt face, then case will expand back over it upon pressure rise. Pretty sure that I read on Internet that was a "poor man's" way to verify headspace - take a case that will chamber - insert a fired primer, but not all the way, and then close the bolt - case shoulder would hit front end of chamber - the protrusion of that primer would tell you the amount of "end play" that was available with that cartridge case in that chamber.

 

[Dogleg]

Not sure if a false shoulder would work on a 9.3X57. The shoulder is already minimal.

Those rifles M46 and M146 have a lot of free bore. Seating the bullet into the lands would be almost impossible.

With all due respect, protruding primers are usually a sign of excess headspace. FYI, this was a max load!

We commonly get protruding primers on low pressure cast bullet loads and there isn't anything wrong with the gun. What's more; short of a crimped in primer most loads have a protruding primer for a micro-second during the firing process. The first thing that happens is the firing pin drives the entire cartridge forward in the chamber. Then the fired primer blows itself out of the casehead until it hits the boltface while the powder is making up its mind. Next, when and if there is a meaningful amount of pressure a combination of the case blowing back and/or case-stretching re-seats the primer and you probably didn't even notice. (Don't blink )In the case of wimp-ass loads like the 303 British, 30-30s, some of my cast bullet loads and frankly yours there isn't enough pressure to move the case and the primer is left sticking out like a whore in church. Granted; in cases of excess head-space a low pressure load will look worse. Put some real pressure on it in the the excess headspace situation and the primer will look like trophy buckle or hub-cap.

Excess headspace can be created or prevented in the loading bench.

Ed should be along soon with some cool pictures.