Salt Bath Annealing Doesn't Work! by AMP

[ntsqd]

Per the second linked article the alloy used in making cases is UNS C26000. Matweb calls it "Cartridge Brass": http://matweb.com/search/DataSheet.aspx?MatGUID=417a313fcec84ec7a54507c813b7fe47

According to this article the alloy would need to contain aluminum or nickel, or both, to harden from quenching from an elevated temperature. Note from the matweb link that UNS C26000 is made of Copper, Iron, Lead, and Zinc. No or only trace aluminum present. It should NOT harden from quenching.
https://www.totalmateria.com/Article71.htm

 

[cmoslof]

as other posters have said, the salt bath must be allowing the hottest temps at the top surface of the bath. Simple solution would be to only submerge the neck and maybe the first .1" of the shoulder.
The other question I had is how did they hold the case in the salt bath? Anything on the case mouth, may act as a heat sink and pull the heat out of that area.
Either way I do think the amp gives the best most repeatable results, but I wouldn't say that salt bath doesn't acheive results either.

You have to remember all the heat to the salt is coming from the sides and the bottom of the pot. The only place heat is being lost is to the case that is inserted and out the top so the top is not hotter, it should actually be the coldest part of the salt.

 

[Hand Skills]

I AM an Engineer. Quenching is used when you're hardening. The whole point of annealing is a slow cool.

Quenching will create stresses by locking in the crystalline structure.

Obviously not a materials engineer.

https://bisonballistics.com/articles/the-science-of-cartridge-brass-annealing

 

[Reloder28]

I purchased the Salt Bath Annealing Kit. I sent an email to the company owner where I purchased the kit and hopefully he will respond.

Don't count on it. I sent numerous e-mails to the guy nearly begging for a response so I could purchase. Never got a response. I blew him off & purchased the AMP MK II & am so very glad I did.

Even if Salt Bath was viable, I would still prefer my AMP.

 

[SMK1000plus]

as other posters have said, the salt bath must be allowing the hottest temps at the top surface of the bath. Simple solution would be to only submerge the neck and maybe the first .1" of the shoulder.
The other question I had is how did they hold the case in the salt bath? Anything on the case mouth, may act as a heat sink and pull the heat out of that area.
Either way I do think the amp gives the best most repeatable results, but I wouldn't say that salt bath doesn't acheive results either.

Let me begin by stating that I have no dog in this fight (yet) but, as Barrelnut alluded to and tailbon3 suggested a fix for, as did LongBomber...

I don't doubt AMP's data per-say, I take exception to their test methodology and the conclusions they draw. AMP's own data shows their testing issue AND the solution to it! Notice chart 2, test positions 4, 5, 7 and 8 of the 550 °C for 8 seconds. The hardness is at or near the ideal (90 to 100) hardness for the case neck! At the beginning of the "testing" they set a submersion depth of 5mm beyond the case shoulder/body junction. Why? Especially when considering the test data and results that they had already collected! There seems to be a lot wrong...

Nowhere in their "well documented" testing do we see any calibrated instrument testing of the salt bath temperature during the testing. Calibrated temperature recording should have been documented throughout the testing and at several depths of the salt bath. AMP's test results strongly suggest that all the salt bath was not up to proper temperature.

AMP's testing also revealed that, not only did annealing take place but, they submerged the cases too deep! Just looking at their test data, it appears to me that (kind of what LongBomber suggested) a single dip for 8 seconds at 550 °C 0.1" above the case neck/shoulder junction would anneal the case nearly perfectly!

How could they possibly miss these issues or not see that their own test data provided all the necessary corrections for near perfect annealing, unless they were intentionally slanting the results to favor their interests.

Who was it that said; "there are lies, d*mn lies, and then there are statistics!"?

JMHO.
Kevin

 

[bigedp51]

If I recall a Rockwell hardness test from Catshooter, Lake City 5.56 was the hardest of any case tested. What's good for military might not be good for our purposes.
As JE says, it's just info, make your own conclusion on what to do with it.

Edit; it does seem strange how a neck could not be annealed but the shoulder over annealed.

My buddy Cat shooter tested the brass hardness in the base of the case and not the neck shoulder area. And this was done to end a argument at accurateshooter because someone said Lapua was harder than Lake City brass.

How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests
http://bulletin.accurateshooter.com...r-brass-5-56-and-223-rem-base-hardness-tests/

Click on image belowto enlarge.

 

[Shootin4fun]

When first deciding which way to go, salt bath or torch, it seemed to me that salt bath would be more consistent. But I decided to go torch. I've had some good results but not conclusive on all sources / caliber of brass.

My persistent question is, when using the torch method what is the proper indicator that the brass has hit the right temperature? I have read many postings/articles and watched several videos but I respect your guys' input here more than most other sources.

Some say keep it in the torch just until the brass takes on a blueish tint, others say until it barely starts to glow, watching with low level lighting. For sure remove before any orange flameout happens.

 

[Barrelnut]

When first deciding which way to go, salt bath or torch, it seemed to me that salt bath would be more consistent. But I decided to go torch. I've had some good results but not conclusive on all sources / caliber of brass.

My persistent question is, when using the torch method what is the proper indicator that the brass has hit the right temperature? I have read many postings/articles and watched several videos but I respect your guys' input here more than most other sources.

Some say keep it in the torch just until the brass takes on a blueish tint, others say until it barely starts to glow, watching with low level lighting. For sure remove before any orange flameout happens.

Below is some brass I recently annealed with a cordless drill, socket, and flame. I always go until I start to see the small blue line on the brass in the pic. I keep the flame right at the neck shoulder junction. Under dim light, I can pick up the end of the the case neck sometimes starting to have a very faint red glow. Time in the flame is about 6 seconds.

 

[Rick Richard]

Don't count on it. I sent numerous e-mails to the guy nearly begging for a response so I could purchase. Never got a response. I blew him off & purchased the AMP MK II & am so very glad I did.

Even if Salt Bath was viable, I would still prefer my AMP.

You apparently did not read where he did respond to me. Go back and read through the threads.

 

[raider1v1]

You apparently did not read where he did respond to me. Go back and read through the threads.

I'm sure we will hear back. There's tons of people with his stuff, me included, that are really hoping AMP is just pulling some shady stuff.

 

[Wedgy]

My persistent question is, when using the torch method what is the proper indicator that the brass has hit the right temperature?
Some say keep it in the torch just until the brass takes on a blueish tint, others say until it barely starts to glow, watching with low level lighting. For sure remove before any orange flameout happens.

Practice with some junk brass in dim light, if you have soldered copper pipe before you know how it heats up unevenly and to spread the flame around, hence the drill and deep well 12 point 1/4" drive socket. I use a lightweight cordless as a big drill gets heavy after a while. Remember from chemistry the hottest part of the flame ? Don't point it right at the case mouth or it will get over annealed before the shoulder does. I point the flame at the shoulder as it takes longer to heat up and will spread to the mouth and all will be equal. Set your torch the same every time, see how long it takes to over anneal a case(a junk one), you can tell by because it will glow orange. You don't want that ! Decrease the time/ temp until it comes out looking like Barrelnuts. Have a digital timer or some way of keeping time, 5-10 seconds, sing a little song or whatever to keep the same dwell time. When I'm set up it's usually 7 seconds in the flame. There are a ton of Youtube videos, good and bad. Play with it, practice on range brass, have fun ! Watch in the video how the neck heats up much faster than the shoulder and how it glows....don't do that ! It's much easier to see with dimmer lighting. I am by no means an expert and others can add some stuff I missed.

 

[tbrice23]

Below is some brass I recently annealed with a cordless drill, socket, and flame. I always go until I start to see the small blue line on the brass in the pic. I keep the flame right at the neck shoulder junction. Under dim light, I can pick up the end of the the case neck sometimes starting to have a very faint red glow. Time in the flame is about 6 seconds.View attachment 134507

Yep.
Looks exactly like mine. I go by faint dull orange glow in a completely dark room.
My torch annealed brass gets 4.5 to 6 seconds depending on manufacturer, case size and case size (self-made annealing machine ). Mine is set on a potentiometer, so once set they all get the same time.

 

[tbrice23]

Practice with some junk brass in dim light, if you have soldered copper pipe before you know how it heats up unevenly and to spread the flame around, hence the drill and deep well 12 point 1/4" drive socket. I use a lightweight cordless as a big drill gets heavy after a while. Remember from chemistry the hottest part of the flame ? Don't point it right at the case mouth or it will get over annealed before the shoulder does. I point the flame at the shoulder as it takes longer to heat up and will spread to the mouth and all will be equal. Set your torch the same every time, see how long it takes to over anneal a case(a junk one), you can tell by because it will glow orange. You don't want that ! Decrease the time/ temp until it comes out looking like Barrelnuts. Have a digital timer or some way of keeping time, 5-10 seconds, sing a little song or whatever to keep the same dwell time. When I'm set up it's usually 7 seconds in the flame. There are a ton of Youtube videos, good and bad. Play with it, practice on range brass, have fun ! Watch in the video how the neck heats up much faster than the shoulder and how it glows....don't do that ! It's much easier to see with dimmer lighting. I am by no means an expert and others can add some stuff I missed.

View attachment 134516 View attachment 134518 View attachment 134519

There's a metronome app.
Thats how I timed it with a drill before I built my machine.

 

[Shootin4fun]

Thanks a lot for the confirmation guys! As stated there are a lot videos on it but they are not all saying the same thing. Blue tint vs faint glow vs stop just before orange flameout. What you have said is what I am doing. My 6.5 looks like Barrelnut's. Not quenching.

I became a bit confused when I moved from 6.5CM to 243 and 270 brass and neither responded the same. Both took 2 -3 seconds longer under same flame adjustment than the 6.5, and didn't end up with much color change. Nevertheless the 243 Remington cases (6th firing, 1st annealing) dropped to 9.7 SD over a 17 case sample.

Using an Anealeez