Serious over-pressure from annealing?

[Texas10]

A propane torch is typically operating at about 3600 *F and brass is a pretty good conductor of heat. Although many use this process in annealing brass, and with good success, I personally fail to see the wisdom of putting that much heat on the brass when small mistakes can have such dire consequences. So I switched over to salt bath annealing for it's consistency, speed, and inexpensive operating costs. I can process 8 to 12 cases a minute and be assured that the cases are not being compromised.

 

[Metal God]

A propane torch is typically operating at about 3600 *F and brass is a pretty good conductor of heat. Although many use this process in annealing brass, and with good success, I personally fail to see the wisdom of putting that much heat on the brass when small mistakes can have such dire consequences.

As noted in my last post if done correctly with the flame placed in the correct spot . Small mistakes will not or at least should not cause catastrophic consequences . I've done a fair amount of annealing this way as well as testing this way of annealing . Although not perfect and or the best way to go about it . again if done right it's quite doable .

Here is some pics of a gas , heat and flame size test I did . These were all done using 308 cases and placing 750* tempilaq inside the necks ( to keep it from being directly in the flame and 450* just below the shoulder .

Here is the propane torch and FWIW this is the socket and drill method .

Just as the case enters the flame

Just as the temp indicators melted both inside the neck and below the shoulder

After leaving in the flame 2sec after temp indicator melted

Note , the longer the case is in the flame or hotter it gets the more yellow/orange the flame gets . I have a theory as to why but it's just a theory with no evidence to back it up . My theory is since zinc melts and breaks down at a much lower temperature then cooper . It's the zinc starting to break down causing the change in flame color . When I say break down I mean "maybe" molecules are burning off the surface of the case not that all the zinc is being destroyed or anything like that .

Here is pics of me trying MAPP gas to anneal . Note : I'm in construction and the MAPP gas I used was my plumbing set up so It likely did not have the best end for the application .

This was right as the case entered the flame . As you can see the discoloration of the flame started immediately and only got worse the longer it was in the flame

Just as the temp indicators melted

2sec after the temp indicator melted

As I write this my computer is glitching I'm going to post this then edit before I loose it all

 

[Metal God]

With out posting all my photos lets just say I did a lot of testing to see what worked and what did not as fare as my temp indicators told me .

Propane was by fare the best and most controllable heat source . The MAAP gas was to hot to start with . Heated the case to fast and it was hard to remove the case from the flame at the correct time . By the time my eyes saw the temp indicator melt and me actually removing the case from the flame . The case neck had already over heated . Not likely by much but the propane was much easier to control .

I also did test trying to see why you get anneal marks and how they happen . My test showed it to be less the case hitting the correct temperature and more the heat of the flame and where it was placed on the case . I had a fantastic photo showing this but was lost to the computer gods .

I do have this photo showing a propane torch turned down low annealing a case . This is right when the two temp indicators melted and is the only photo I have that shows the actual tempilaq on the case as it melted . Note there are NO anneal marks on the case and yet the case reached the proper temperature .

This was all done several years ago and I marked and saved all the cases . Some day I plan to size , load and fire them to see what happens when the cases reach different temps during anneal in this way . The OP has shown us what happens when you get the heads to hot haha . So I guess I'll be looking at bullet hold and release as well as consistency of sizing ( bumping the shoulder back . Thanks to the OP I do not need to blow up my gun to show something I believe I already know lol

 

[Webster]

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 .
W MAPP gas is to hot for annealing or at least heats the case up to fast to control consisten
tly IMHO .

To overheat the case head and soften it more than a few hardness units it would have to be at 750F for more than 5 minutes.

Everyone is using different hardness scales. Cannot find the University of Illinois website with the full report. If you assume 10% deformation of the case neck 5-15 seconds in the 400-450 Centigrade range there is very little drop in hardness.

 

[Webster]

A propane torch is typically operating at about 3600 *F and brass is a pretty good conductor of heat. Although many use this process in annealing brass, and with good success, I personally fail to see the wisdom of putting that much heat on the brass when small mistakes can have such dire consequences. So I switched over to salt bath annealing for it's consistency, speed, and inexpensive operating costs. I can process 8 to 12 cases a minute and be assured that the cases are not being compromised.

Propane torches work the best for small soldering or heating jobs because of their portability. While propane-oxygen combinations can reach a maximum temperature of 3,623 degrees F, or 1,995 degrees C, a propane-butane torch only goes up to 2237 degrees F, 1225 degrees C. A torch flame consists of two cones, an outer light blue flame and an inner dark blue flame. The hottest point in the flame can be found at the tip of the inner flame.

3623F Propane with an oxygen tank.

 

[DLT]

My uncle has the exact same thing happening to his 224 Valkyrie. All was well until he annealed his brass for the first time. Primers are blowing out, getting belted cases and big time enlarged primer pockets as well as flash holes well before the max we went doing a ladder. Was this problem ever resolved ? Thanks

 

[Dave M.]

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!

This is some of the worst written advise and knowledge on annealing that I’ve ever read. I know the post is old but I hope the forum boss reads this and deletes this post above before someone follows his direction (ie sort of soften the brass head) and blows themself up when they get a serious case head separation. No offense intended but some folks should consider doing more reading and less posting. I apologize if it sounds harsh but the advice above is downright dangerous.
Dave

 

[Ray123]

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

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

My hornady manual says 224 Valkyrie 27.5 gr of CFE223 is max for a 60 gr vmax 3100 fps out of 22 " barrel.
So I'd try 27.5 gr or less in your cases... no powder listed for that bullet goes over 28.9 gr which is Leverevolution for top velocity of 3200 fps..
According to Hornady.

 

[Webster]

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.

The original post was 3 years ago.

 

[paulT]

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

Do you anneal with one or two gas torches.

 

[big5ifty]

Annealing has nothing to do with over pressure.

Donuts. Look, and ye shall find.