AMP AZTEC Mode Question

[R.Morehouse]

I had the orig. AMP and it worked well. I sold it to a local guy and am thinking that wasn't the smartest decision now that I am looking into doing more longer-range shooting.
My question is for you guys using the AZTEC Mode.....After your initial piece of brass is tested, and your setting is secured, after a number of firings on the brass have you run one through AZTEC to see if your setting changed?.......Thanks

Regards
Rick

 

[jepp2]

After your initial piece of brass is tested, and your setting is secured, after a number of firings on the brass have you run one through AZTEC to see if your setting changed?.

I don't, and for those that have the readings don't change any more than if you initially tested more than 1 case from the lot (normal variability of case to case + test variation).

 

[dgeesaman]

I had the orig. AMP and it worked well. I sold it to a local guy and am thinking that wasn't the smartest decision now that I am looking into doing more longer-range shooting.
My question is for you guys using the AZTEC Mode.....After your initial piece of brass is tested, and your setting is secured, after a number of firings on the brass have you run one through AZTEC to see if your setting changed?.......Thanks

Regards
Rick

I’ve done it and it changed a few points on the scale, but then I tested a couple more and found it was all within the overall repeatability of the testing method. Now I test one and use the same setting without checking again.

David

 

[R.Morehouse]

So with normal case to case variation, do you think the AZTEC is really all that more accurate than the orig. AMP with the factory listed settings for your chosen brand of brass etc.?

 

[RustyInBend]

Same as others ... my subsequent firings had such a slight variance in the returned code, that I've settled on my numbers and have stopped sacrificing cases to the God of the Aztecs.

 

[gldprimr]

I found it informative that you should run Aztec mode on fire formed cases. Just used my new AMP annealer the first time this past week and did run the Aztec mode on a fire formed case to get the correct setting. Link to AMP annealing video below on using Aztec mode on fire formed cases.

 

[RegionRat]

So with normal case to case variation, do you think the AZTEC is really all that more accurate than the orig. AMP with the factory listed settings for your chosen brand of brass etc.?

It is sensitive enough that if you sort brass and test the lightest, middle, and heaviest ones, you will get a proportional difference in the resulting code. Unless you are matching the code you are using to the average weight of the samples AMP used when generating their value, you will be a little over or under done. However, I that isn't to say using the older system is bad.

I recently sorted some Fiocchi 223 brass that came from factory varmint loads. It was not a good quality batch and there were roughly 25 split necks per 1000 pieces so the thought was that annealing might help reduce further neck splits when reloading them. (Still lost roughly 2 pieces per thousand during loading).

After inspecting a random sample of 30 pieces for the weights, the heaviest, average, and the lightest ones were tested for the AZTEC codes to see how sensitive it would be to the weights.

Here is an example of the weight of the sample case and the resulting AZTEC code.
Weight in grains Code
99.7 135
98.6 134
97.1 133

The batch was run on Code 134. I then checked the difference in the hardness of the necks on light and heavy brass and their microhardness values were less than the noise level in the hardness test with values for all of them roughly 90 - 93 on the hardness scale. Considering how bad they were before annealing, I was pleased.

 

[jepp2]

So with normal case to case variation, do you think the AZTEC is really all that more accurate than the orig. AMP with the factory listed settings for your chosen brand of brass etc.?

Absolutely! All you have to do is go to the Peterson website and look at their Aztec readings. They list them for every batch they produce starting a few years ago.

 

[quest450]

I'm getting ready to prep another batch of BRA brass
6BR Norma Lapua cases, fireformed than necks uniformly turned to 0.011"
I'm very interested to see how the weight of a case can affect the AMP Aztec # after necks are turned
I just don't see how weight of the case can make that much of a difference since the AMP is just testing "burning" neck/shoulder area to get the Aztec code,
IMO case weight mostly differs around case webb and the thickness of the extraction grove not around neck/shoulder area especially after turning the necks

 

[RegionRat]

I'm getting ready to prep another batch of BRA brass
6BR Norma Lapua cases, fireformed than necks uniformly turned to 0.011"
I'm very interested to see how the weight of a case can affect the AMP Aztec # after necks are turned
I just don't see how weight of the case can make that much of a difference since the AMP is just testing "burning" neck/shoulder area to get the Aztec code,
IMO case weight mostly differs around case webb and the thickness of the extraction grove not around neck/shoulder area especially after turning the necks

It would be easy to throw off the concept if you weight sorted and then neck turned.
In the above discussions, the brass wasn't turned.

If the necks are not turned, their weights clearly correlate to the codes.

There are other factors with induction, but within a headstamp, the weight stats matter.

I would suggest that if you bother to turn necks, you are probably picky enough to weight sort too. Then the code should be generated only on the turned necks.

 

[quest450]

I do agree, there seems to be correlation between unturned brass and Aztec codes as you've posted above.
I think a lot of benchrest shooters do turn necks although I see a trend lately to go with .272" no turn neck chamber where I could see the case wight having more of an effect on Aztec code due to brass thickness and weight variation.
I no longer weight sort brass, It's a misleading number
I do sort my trimmed and uniformed brass after couple of firings using the internal case capacity measuring tool by Bison Armory.