Aztec numbers vary.

[EdHarley]

I am trying to get an aztec mode number for the 7-6.5 PRC with Lapua brass and Peterson brass. I checked a piece of Lapua 6.5 PRC brass out of the box and it gave me 183. I then checked a piece after necking up, sizing, chamfer and deburring and the number was upper 140s I think. This seemed a little low given the color change on the brass did not appear to travel down the shoulder and case body nearly as much as the other types of brass so I redid it with another piece prepared the same way and it gave me 173. This is way off from the first number. I am very happy with the AMP machine and have not seen nearly as much disparity even between different brass types within the same caliber. So, what I am wondering is if there is consensus on the Aztec number for the 7-6.5 PRC Lapua brass such that I can quit wasting my brass to get a number?

 

[rwj]

AMP recommends using the Analyze mode on cartridges fired in your chamber to generate an Aztec code number. Different neck diameters will generate different Aztec code numbers.

 

[Rook 6]

The AMP is very sensitive to the piece of brass being analyzed. Fire formed vs out of the box makes a difference. Turned vs not turned makes a difference. If your brass is all from the same lot, which I assume it is, my recommendation would be to analyze a piece of fired brass and just go with the number. You want to anneal before you resize.

 

[TylerFromMS]

Put a fired piece in. It’s what AMP recommends. With the Lapua you’re going to have to add to the code to shoulder bump consistently more than likely.

 

[EdHarley]

Good point. This was unfired brass.

 

[jepp2]

I checked a piece of Lapua 6.5 PRC brass out of the box and it gave me 183. I then checked a piece after necking up, sizing, chamfer and deburring and the number was upper 140s I think.

I am not suggesting that you did this, but when I see Aztec numbers that are wildly different, I always wonder if somehow a different "analyze" code was entered. The differences for sized vs unsized, neck turned vs not turned, will be different but not nearly as dramatically as some have seen. Just thinking out loud.

 

[rwj]

I am not suggesting that you did this, but when I see Aztec numbers that are wildly different, I always wonder if somehow a different "analyze" code was entered. The differences for sized vs unsized, neck turned vs not turned, will be different but not nearly as dramatically as some have seen. Just thinking out loud.

You will definitely get widely varying Aztec codes if you enter the wrong pilot number! I did as evidenced by a melted case!

 

[ballisticdaddy]

AMP recommends using the Analyze mode on cartridges fired in your chamber to generate an Aztec code number. Different neck diameters will generate different Aztec code numbers.

Anybody get a repeatable Aztec code? Seems every piece of brass generates a new code. These have been sonic cleaned but not neck turned nor sized but still can't get it to repeat the original code.

 

[NZ_Fclass]

I will ring Matt and ask. Interesting thoughts. Don't forget that the colour will affect the heating too - a dirty neck will attract more heat. - I did have the impression that the codes were unique and not a scale - but I will find out.

 

[EdHarley]

You will definitely get widely varying Aztec codes if you enter the wrong pilot number! I did as evidenced by a melted case!

That’s true, good point, although I am pretty sure I used pilot #20 for all 3 of them

 

[EdHarley]

Anybody get a repeatable Aztec code? Seems every piece of brass generates a new code. These have been sonic cleaned but not neck turned nor sized but still can't get it to repeat the original code.

How far apart are they? I am ok if it is two or three numbers off but twenty? I don’t understand that.

 

[jepp2]

although I am pretty sure I used pilot #20 for all 3 of them

Just for clarification, you are entering the analyze code, not the pilot. You just screw the correct pilot in the machine. And for the sake of this, you would enter 020C, and if you enter 020A, or 020B or any other incorrect analyse code, the result will be WRONG.

I find excellent correlation between different lots of the same cartridge & brand.

 

[EdHarley]

Just for clarification, you are entering the analyze code, not the pilot. You just screw the correct pilot in the machine. And for the sake of this, you would enter 020C, and if you enter 020A, or 020B or any other incorrect analyse code, the result will be WRONG.

I find excellent correlation between different lots of the same cartridge & brand.

View attachment 1528871

You may have found the problem but I am pretty sure the machine asks for the Pilot number.

I just looked it up in the directions and you are correct. Crap, I have been giving the pilot number not the analyze code. Thank you for pointing this out. Now that you mentioned it, I remember looking them up when I first got the machine and tested all my different types of brass but it has been some time since I had a new caliber. Now to waste another piece of brass.

 

[EdHarley]

So now what would one do if the number they used to anneal their brass was significantly higher than what it was supposed to be, redo the annealing with the correct number? As I understand it using a much higher Aztec code will soften the brass too much based on a video someone posted in another Aztec thread.

 

[rwj]

So now what would one do if the number they used to anneal their brass was significantly higher than what it was supposed to be, redo the annealing with the correct number? As I understand it using a much higher Aztec code will soften the brass too much based on a video someone posted in another Aztec thread.

I’d direct that question to AMP. Their prompt are responding/providing guidance. Just remember the time zone difference!

 

[Nealm66]

I’ve done it accidentally a couple times. I suspect it varies by cartridge/bullet jump and shoulder bump but I can tell you a 6.5-300 won’t shoot very good. I’ve had some success work hardening the brass with a full length sizer to bring the neck tension back. I just recently put in the wrong code on some 300 wm and will see if work hardening will help but bought new brass anyways

 

[EdHarley]

I discussed the wrong code question with the AMP people. They were very helpful. It is best to use fire formed brass as noted earlier. They said the proper code for the 7-6.5 PRC is 020A. The proper code for the 6.5 PRC is 020C. It looks like I accidentally used the proper code just not after fire forming but before.
If you have been using the 6.5PRC code that is OK:

“020 C gives a number +3 higher than 020 A. No harm done if you used that.”

I then asked what harm may have come from the annealing with the wrong code and he reassured me that it will be fine. Just shoot it and anneal again before sizing.

”Fire formed cases will give you a slightly lower number than virgin or sized. In the meantime, your cases will be fine. Go ahead and shoot them, then sacrifice a fire formed case to get the correct code for future cycles.”

As far as when to anneal in the reloading process:

“You should always anneal prior to sizing. That will give much more accurate and repeatable neck tension and bump. See:

https://www.ampannealing.com/articles/55/annealing-under-the-microscope/

https://www.ampannealing.com/articles/56/annealing-under-the-microscope/

There is a bit of a trend for guys to anneal a second time after sizing. We are not sure if that is necessary, but we will be doing a project shortly to find out.

As for work hardening, see:

”

 

[Fire Dog]

I will ring Matt and ask. Interesting thoughts. Don't forget that the colour will affect the heating too - a dirty neck will attract more heat. - I did have the impression that the codes were unique and not a scale - but I will find out.

I clean every time before annealing... Have found the original Aztec code for a given lot of brass to be correct for the life of the brass.