Serious over-pressure from annealing?

[J F Johannes]

I believe that's .223 data; he's shooting a .224 Valk. He's on the upper end of their charge weights, but nothing crazy.

oops..... missed that, sorry. Still max load for the 224V.

 

[243winxb]

Trying to match factory velocity is not always a good idea. The pressure may be very different.

Change one component, different bullet, pressure changes.

I am still thinking trim length is to long??

 

[Texas10]

You pulled and double checked the charge in the remaining cases of the batch that is dangerously overpressure. So you've confirmed that no mistake was made on the that loading, however I suspect the error was made on the development loading instead, or a possible mistake in your record keeping.

Other possibilities are different powder lot, different powder altogether. There is no doubt in my mind that a simple mistake is at work here. I use a balance scale, will sometimes set the poise one grain off, get to the range and wonder why my load is shooting all over the place. I've also grabbed the wrong powder bottle, which I leave on my loading table during use, look up and say WTF is that powder doing out? Then start pulling down.

More caffeine please....

 

[C.E.Smith043]

Was there a change in air temp or altitude?

 

[hboothe]

Check chamber length and brass trim length. Long brass, short chamber, bullet crimped by chamber on loading.

Not keeping brass sorted by times fired is something to watch. I would not mix.

It may take up to 5 firings for primer pockers to expand. Your load seems to be maximum?

Thanks for the reply and sorry to all for the hiatus in responses. In the midst of trying suggestions (from here and those my mind conjured while reading replies), I temporarily bricked my rifle when an ejected primer jammed the BCG.

This brass was decapped, cleaned, sized, trimmed, all as one process for maybe about 100 cases, more than I loaded here. Others from this batch of brass have exhibited zero problems. 29.2gr of CFE-223, per Hodgdon's website, for the 224 Valkyrie, for a 62gr SFT SCIR (whatever that is) is maximum. I loaded cartridges at 0.2gr increments below this (I recall it being 0.2, it might have been 0.3), for 5 different weights. I loaded 2 per charge weight and shot them over a chronograph. Each cartridge was marked with which charge weight it contained, each spent casing went carefully back into the container (MTM Case-Gard), and each cartridge was carefully inspected back in the shop under bright light. 29.2 showed slight/moderate primer flattening, no other obvious signs.

--HC

 

[hboothe]

I'm sure the answer to this is no, but I'll ask anyway...Not trying to imply anything by it.

New lot of powder, or bullets? Any chance you cleaned the barrel, and maybe left the chamber a little wet?

Where I'm getting at is that annealing shouldn't cause that, so I'd be looking elsewhere.

Thanks for the reply. No worries, I'm always open to suggestions if people will just be polite about it. This should not be a different lot of powder but...I have several containers of CFE-223, so it's possible, but not terribly likely. Same box of bullets. As for the chamber: no, I don't think so as this occurred across several rounds being fired, even some factory ammo in the sandwich of my reloads (hunting and testing).

The day I posted this, the BCG jammed with a blown primer and I FUBAR'd the charging handle trying to get it open. I was in the middle of some testing. First, I grabbed one of the process batch of brass and loaded the powder (double measured) and bullet and fired it. It looked "normal" (slight/moderate primer flattening). Then, I grabbed 4 cases from the same processed batch, annealed 2 of them per my "normal" way, and 2 were left untouched. I then primed and carefully measured out the 29.2gr of CFE-223 for each (electronic to near weight, balance beam to trickle to final weight). I then alternated them in the magazine and was attempting to shoot them when the BCG got jammed up. The first one, not annealed, fired fine and looked "normal" (slight/moderate primer flattening), the annealed one was FUBAR (like the others which were annealed), and that was the end of my testing (jammed).

Posts here, my own (weird) thought processes, and some further reading on the subject gave me an idea: measure the results of the annealing. Specifically, measure the heat which reaches the case head. Yes, the horse *should* go first.... The Tempilstik's arrived today and I tested the case head with 343C and 454C sticks after heating the brass "normally". The 454C stick smoked a touch but did not melt. The 343C stick melted a little bit. I'll go back and double check my numbers, but I don't recall 343C being hot enough to actually anneal the brass in a short period of time. Maybe over an hour, but not 15 seconds of heat up and cool down. I could be wrong. What I should do, at this point, is prime an annealed cartridge and then put a bullet in it, no powder, and fire it in the rifle to see if the bullet lodges in the barrel. But sobriety is holding me back...but I should. But it's my favorite/daily-use hunting rifle...y'all have a beer for me and see if it loosens me up.

--HC

 

[hboothe]

Over-annealed case = too soft brass.
Too soft to handle the pressure you have.
You may actually not be over pressure for good brass but that soft brass wants to run somewhere when fired.

Thanks for the reply. Yes, I totally agree. And I totally thought I wasn't screwing it up. I got some Tempilstiik's and tested three cases immediately after heating them. 343C melted a little bit, 454C smoked almost imperceptibly. I didn't think 343C-350C would anneal/soften brass for the few seconds it was subjected to the temperature (15 seconds or less). I'm going to read some on that to see if I'm incorrect.

--HC

 

[hboothe]

Wimpy neck tension would not be the cause for your angst. Upon primer explosion the primer is jammed into the rifling (leade) and the entire powder charge is like an uncompressible liquid plastered forward with bullet immediately prior to powder combustion. Wimpy neck tension or tight (short of welding the bullet in place) this would happen no matter what. Are your bullets in place after shoving the loaded rounds into the magazine and COAL unchanged after stripping a loaded round from magazine into chamber? I did see some reference to crimping.

My suggestion would be to look at annealing for making those brass heads sort of soft (annealing). The real big question - were the cartridge brass heads protected from the 2000 plus degree heat blast of the propane torch (assuming propane was used)?

Annealing, crystal size, work hardening, tough hard springy brass heads, primer pockets, signs of annealing by colors just below shoulder to mouth all good stuff to know about - "forensic analysis", has always scared me real bad no matter what, legions of lawyers, court testimony, depositions, pressure…. Should I be compelled to perform any "forensic analysis" on my ammo production factory loaded ammo would be the only option.

Take care and make good ammo!

Thanks for the reply. My (admittedly limited) understanding is that the primer can displace the bullet upon ignition in certain, but not all, situations. BR primers, purportedly, are designed/built for low neck tension use as in Benchrest, so that primer ignition doesn't dislodge the bullet before the powder burn has the opportunity to do so. I can speculate until we run out of Internet storage on that: I'm just sayin' what I read. If that is true (I read it on the Internet so it has to be true, right?) then it's possible for a full-power (CCI says to treat the #41 as a "magnum primer") to dislodge a loosely-held bullet. Maybe. The points are these: 1) I've got conflicting data about this and 2) please don't take offenxe, I'm not trying to step on you, just voicing thoughts, not proven facts.

Some of the first replies were regarding whether the bullets migrated upon chambering and extraction and the answer was: No. The bullets held their ground or moved 0.0015" (1.5 thousandths).

I got Tempilstik's today (via Amazon) in 343C and 454C. I annealed 3 cases in the same fashion as before and immediately tested the case heads. 343C melted slightly on all three, 454C smoked almost imperceptibly on them. So, my homework is: will 343C anneal brass (soften it) appreciably in 15 seconds or less?

My take on your comments re "annealing, crystal size, work hardening..." is this: It's all gray. Yes, Virginia, I fear it is all gray...but there is Santa Claus. I was hoping, I guess, that annealing would be more black and white, simple, easy. Apparently it's easier to get an accurate answer to which cartridge is the best. <GRIN>

--HC

 

[243winxb]

immediately tested the case heads. 343C melted slightly on all three, 454C smoked almost imperceptibly on them.

Tempilstik's doesnt get placed on the case head. If thats where your applying it? I may be confused.

205C would be maximim on the case head.

 

[47WillysGuy]

Thanks for the reply. Yes, I totally agree. And I totally thought I wasn't screwing it up. I got some Tempilstiik's and tested three cases immediately after heating them. 343C melted a little bit, 454C smoked almost imperceptibly. I didn't think 343C-350C would anneal/soften brass for the few seconds it was subjected to the temperature (15 seconds or less). I'm going to read some on that to see if I'm incorrect.

--HC

Please describe your annealing equipment and annealing process.

How do you hold a steady 650 degrees for 15 seconds on the case neck?

If the case head (primer end) is at 650 degrees, that’s way to hot. Only the case neck should be heated and what heat migrates to the case head (primer end)is minimal. I turn a case neck dark red in 6/8 seconds with a propane torch. Bright red in 10-15 seconds which makes case neck to soft to hold the bullet in an interference fit and is rejected.

 

[argh]

Im with 47 willies. Describe your annealing process. If your case head is getting annealed it will be soft and expand during firing.
The description of what is happening to your cases is an exact match of what would happen if you are annealing the entire case, and not just the neck.

 

[Evan]

You've done a couple tests now showing annealed cases failing, and non-annealed cases working fine. The answer to your problem is that you're over annealing the cases and damaging the structure of the case head. Less heat!

 

[XTR]

Just for reference, annealing my 308s and 223s with a Benchsource the case is in the heat for just under 4 seconds to just over 2.5 respectively.

 

[Bob L.]

When I annealed 6 BRX cases with my Benchsource, the times were about 3.5 seconds, in the same ball park as XTR.

 

[fyrewall]

Thanks for the reply. My (admittedly limited) understanding is that the primer can displace the bullet upon ignition in certain, but not all, situations. BR primers, purportedly, are designed/built for low neck tension use as in Benchrest, so that primer ignition doesn't dislodge the bullet before the powder burn has the opportunity to do so. I can speculate until we run out of Internet storage on that: I'm just sayin' what I read. If that is true (I read it on the Internet so it has to be true, right?) then it's possible for a full-power (CCI says to treat the #41 as a "magnum primer") to dislodge a loosely-held bullet. Maybe. The points are these: 1) I've got conflicting data about this and 2) please don't take offenxe, I'm not trying to step on you, just voicing thoughts, not proven facts.

Some of the first replies were regarding whether the bullets migrated upon chambering and extraction and the answer was: No. The bullets held their ground or moved 0.0015" (1.5 thousandths).

I got Tempilstik's today (via Amazon) in 343C and 454C. I annealed 3 cases in the same fashion as before and immediately tested the case heads. 343C melted slightly on all three, 454C smoked almost imperceptibly on them. So, my homework is: will 343C anneal brass (soften it) appreciably in 15 seconds or less?

My take on your comments re "annealing, crystal size, work hardening..." is this: It's all gray. Yes, Virginia, I fear it is all gray...but there is Santa Claus. I was hoping, I guess, that annealing would be more black and white, simple, easy. Apparently it's easier to get an accurate answer to which cartridge is the best. <GRIN>

--HC

In response.

To my best knowledge BR primers contain the same amount of explosive and standard primers. I have a site that shows the energy generated by primers upon detonation. I will dig this up and post it for your info. Sophisticated measurements done by established professional.

Me taking offence, no, not at all. I just eat this back & forth stuff up.

On the Tempilstik testing does 343C refer to 343Centigrade? 454C refer to 454 Centigrade? - I have never used the stuff, relying on submerging cartridge heads in 1/2 inch water.

343 degrees Centigrade = 649.4 degrees F, 454 Centigrade = 849.2 degrees F ; propane flame temps, depending on air/oxygen mixing is about 2200 degrees F. Possibly, those brass heads were annealed and softened then at a chamber pressure of 55,000 psi the primer pockets expanded.

If I could look into brass and see what happened to crystals upon work hardening or annealing I would be lots smarter about this. I use a ring type propane flame tip and expose the brass surfaces to the tips of the flame (lots of little flame jets); this part of the flame is the hottest. After 15 seconds I flip the cases into the water and hear them sizzle. The annealing reduces brass spring back upon sizing the neck and my bullets are securely held. Brass life is also is extended. The force to seat bullets appears to be very uniform after annealing.

The Remington 7 1/2 BR primer is one frisky primer. Take care.



I

 

[fyrewall]

Regarding BR type primers contributing to the problem:


https://arxiv.org/ftp/arxiv/papers/1410/1410.6390.pdf



Here is more primer stuff
https://arxiv.org/ftp/arxiv/papers/1102/1102.1644.pdf



--HC[/QUOTE]

Don't toast those brass heads - I like to stand them up in 1/2 inch water in Grandma's old ss brownie pan - brass is a real good heat conductor and the propane flame is probably about 2300 degrees F.

Take care

 

[hboothe]

Hey, all, I'm having a problem with some rounds I loaded for a 224 Valkyrie in an AR-15 platform and I'm wondering if annealing the cases has something to do with it.

I am loading 60gr Nosler BT Varmint bullets in used brass over 29.2gr CFE-223, CCI #41 primers. I use these for hunting, switching from the factory Federal cartridges, and I go through 20 or so each week. I had worked up the load from down around 28gr powder, shooting over a chronograph, finding which amount of powder would get me the velocity I wanted and looking for pressure signs (specifically: flattened primers, extractor/ejector extrusion, ejector swipe). I found that 29.2gr of CFE-223 gave me a slightly flattened primer, good velocity (similar to the Federal factory stuff), and no other signs of over-pressure.

I got good groups from the test batch and decided to load up 50. Considering that this is a hunting rifle and also an AR-15, I always full-length resize my cases. Furthermore, considering that I do not sort, organize, and log "rounds fired", some of these may be on their 3rd or 4th or 2nd or whatever trip through the rifle...so I thought annealing the cases might be a neat idea. So, I annealed them. I loaded them with the same load/components I'd used in the workup. And they are dangerously over-pressured! Jeez, I shot 3 of them, 2 before I noticed the problem and 1 afterwards to "be sure", and all three: blew the primer out and expanded the case head. I mean, I can see where the chamber ends support for the case, and the primers can be put back in by just dropping them in. Wow!

I pulled 5 of cartridges randomly and weighed the powder charges, in case I made a dumb mistake in the loading, but, no, 29.1 and 29.2 grains for each. I had the correct powder and primer and seating depth. I noticed the seating effort was seriously reduced when I loaded the annealed cases (I used a light crimp with a Lee FCD like usual for the AR-15), and, of course, pulling them apart is easy, too. I had stuck a bullet in a naked case in the reloading process to compare bullet seating effort and, when I pulled it apart, I noticed that the effort was significantly higher to remove the bullet from the case.

So, my question then is: what happened? My best guess is that the reduced neck tension allows the bullet to slide forward either with the primer discharge or otherwise dramatically earlier on in the powder burn and, therefore, is jamming on the lands and causing a serious spike in chamber pressure.

I'd like to see what insight/thoughts you folks might have. Also, if it is just the neck tension causing the change (in this case, from annealing), then this might serve as a warning to others.

Thanks for your time.

--HC

Finally I'm back to report what I've found, apologies for the delay.

First, I was overheating the brass considerably during my attempted "annealing". The case head caused melting of my 343C Tempilstik, and that's hot enough, from my reading, to relax the brass (brass can relax/soften at lower temperatures, apparently, and actually anneal at lower temps than we shooters normally use, if given a long enough time...it's complicated). To test things out, I pulled bullets from a number of cartridges and verified them to have the correct amount of powder. I put new powder back into the cartridges from the correct container and in the correct amount (just to be 100% certain). I did the same with some cleaned but not annealed brass and attempted to fire the cartridges. I fired the un-annealed (U) then the annealed (A) and tried to alternate. I shot U then A then U then...jammed action. The second U cartridge dumped its primer into the action and jammed it up. I was done at that point. The final info from that session was: the U cartridges fired fine and were not over-pressure, the brass was not ruined, birds still sang; good to go. The A cartridges were toast. Every one I fired (this test sample and the ones before I realized I had a problem) were ruined.

Secondly, I stripped 3 cartridges from the annealed batch and put only the bullet back (no powder). I "fired" all three cartridges in my rifle to see if the primer had sufficient power/force to lodge the bullet in the chamber/throat/leade/thingy. Two cartridges only set the bullet forward (varying amounts up to a couple hundredths of an inch) but one lodged the bullet in the bore somewhere close to the chamber (it was easy to knock out with a rod from the muzzle end). This lends some credibility to the idea that primer could push the bullet into the bore before the powder was well initiated, obstructing the bore and causing a pressure spike on an already-hot load. It's just supposition, like "all unicorns are left hooved" and "weathermen know what the weather will do".

Regardless of the "bore obstruction" maybe yes/maybe no thing, I screwed up the "annealing" thing. And how. Let this be a warning and a lesson to others: "Yes, Virginia, you can royally screw the pooch by overheating the heck out of your brass." Even for a few seconds, on small cartridges anyway. Oopsy.

--HC

 

[47WillysGuy]

“Regardless of the "bore obstruction" maybe yes/maybe no thing, I screwed up the "annealing" thing. And how. Let this be a warning and a lesson to others: "Yes, Virginia, you can royally screw the pooch by overheating the heck out of your brass." Even for a few seconds, on small cartridges anyway. Oopsy.”

Glad you didn’t hurt yourself.

 

[dellet]

I don’t know anything about the 24 Valkyrie, but enjoy troubleshooting threads. I think checking the basics might be in order.

If I read the SAAMI chamber drawing correctly with 1.7836” being bore diameter and your base to ogive is 1.8+, you’re likely jamming the bullet.

That explains both the over pressure and the growth when chambered.

https://saami.org/wp-content/uploads/2018/04/224-Valkyrie.pdf

 

[Metal God]

Interesting that you annealed the head to much . I did some test on trying to do so and found it to be very hard to do so .

These are 308 and 223 cases . I put 750* just below the shoulder and 450* just above the head . I then annealed the crap out of the shoulders . When I say that I mean the neck was glowing red for several seconds and I still could not get the heads hot enough to melt the 450* tempilaq above the heads . I concluded that if you held the flame in the right place it was almost impossible to over heat the heads . The reason is because you would have over annealed the necks and shoulders to dead soft basically ruining the case or reloading anyway ,especially if loading for a semi auto . I mean look at those necks , they are cooked !

So how did you over heat the head by holding the flame on the neck and shoulder ? How long was the shoulder in the flame and what gas did you use ? FWIW MAPP gas is to hot for annealing or at least heats the case up to fast to control consistently IMHO .