What AMP Aztec Code for Lapua 6 Creedmoor Brass?

[Senor_Barney]

Updated: Not sure what to make of this.

I have since run Aztec analyze mode on five pieces of Lapua 6 creedmoor brass on Pilot / Analyze Setting 017B. Each $1.25 piece of brass that I've sacrificed has yielded different results.

Brass #1 0155
Brass #2 0167
Brass #3 0150
Brass #4 0172
Brass #5 0152

This was performed back to back on five pieces of brass from the same box (Lot LPT01413-1). Once fired, deprimed and cleaned.

FWIW, my Alpha Dasher brass code is 0143 and my Peterson 300 Norma Mag brass code was 0170.

I'm curious if any other AMP users can chime in on Lapua brass for 6.5/6 Creedmoor.

Below is three pieces at 0167 code

 

[J McGriddle]

0168 - Lapua 6mm Creedmoor Lot 2403518

 

[Rillhurst]

Lapua 6.5 Creed
0160

 

[918v]

I got 155 on a small primer 6.5 case and 157 on a large primer case.

 

[Senor_Barney]

155...160...168.........

 

[918v]

Measure the extractor groove diameter of the brass, the case head diameter, and the rim diameter. Weigh the remaining brass and see if maybe this lot is mixed.

 

[918v]

Well???

 

[OREGUN]

Measure the extractor groove diameter of the brass, the case head diameter, and the rim diameter. Weigh the remaining brass and see if maybe this lot is mixed.

Dude that’s brutal. Brilliant, but brutal.

 

[OREGUN]

STOP KILLING EXPENSIVE BRASS!!!!


Just pick the middle number and use it. Or, you got 155 twice? Use that.

Or the AMP squad is super responsive, email them and ask what they think.

Or do what I do and only kill one piece from a box and just use that one number….literally it has never occurred to me to do a bunch until a custom reload shop owner said “so you start by running analyze on at least five pieces right?”

ummm….errrr. Yeah, of course I do.

 

[HemiPowrd]

Lapua SRP 6.5 CM - 160

 

[JBattles]

Lapua 6BR 0160

 

[918v]

STOP KILLING EXPENSIVE BRASS!!!!


Just pick the middle number and use it. Or, you got 155 twice? Use that.

Or the AMP squad is super responsive, email them and ask what they think.

Or do what I do and only kill one piece from a box and just use that one number….literally it has never occurred to me to do a bunch until a custom reload shop owner said “so you start by running analyze on at least five pieces right?”

ummm….errrr. Yeah, of course I do.

That will produce brass with variable neck and shoulder hardness defeating the reason he got the AMP.

 

[OREGUN]

That will produce brass with variable neck and shoulder hardness defeating the reason he got the AMP.

So the answer is to Aztec every piece?


I think, personally, that consistency is better than a one or two or five number level of accuracy with the amp. Doing all the pieces with a different code would be dumb…being off from the perfect Aztec code by a half dozen numbers matters less. Even AMP will tell you you can go up and done a bit to suit your preference. If you’re worried about over-annealing, pick a smaller number from the set. If the brass is analyzing differently per every piece, you are going to “produce brass with variable neck and shoulder hardness defeating the reason“ to have an AMP anyway. At some point you have to pick a number and use it. Any number is literally better than some “hold it in the flame until it glows the color of a ripe pumpkin” bullshit.

I could be wrong. I’ve never analyzed more than one piece from any lot, after two firing/sizing cycles, as directed by AMP. I’m getting all of the benefits of annealing (long brass life, consistent neck tension) and SDs in the single digits over as many rounds as I feel like sending past the chrony. So, what are we doing, loading to shoot or loading to analyze meaningless minutiae?

 

[OREGUN]

In fact, I’d go so far as to say if he picks 155 and 172, from his numbers, and does half his brass with one and half with the other, AND can show any measurable difference between the two, in any metric he chooses, I will replace the box of brass for him.


ETA: metric related to shooting. Accuracy, longevity, consistency, for example. I don’t really care about the laboratory-tested brass hardness is or the force required to crush a case mouth or whatever.

 

[918v]

I’m not saying he should analyze everything. I suggested he measure the brass to see if he has multiple lots mixed in there. Then sort it and analyze one from each batch.

 

[OREGUN]

Do you honestly think that a consumer grade measurement of the dimensions you specified will be a better indicator of brass lot than taking five pieces out of a box with the lot number printed on it? I mean, he did say they were from the same lot…and had the lot number. If we can’t trust Lapua to label their case lots accurately, then the whole need for Aztec is moot.

Maybe he could submit the brass for testing in a lab somewhere to determine if the brass has the same chemical/physical properties. But measuring the case head diameter and extractor groove diamter? I honestly thought you were cranking him up. At best, from that, he ends up with a long list of numbers that are all over a +/- range and don’t relate to brass manufacturing lots at all.

 

[918v]

I have found that brass from the same lot tends to have the same dimensions.

 

[OREGUN]

well shit. now I have to go measure some brass.

 

[Senor_Barney]

Update:

I reached out to AMP to share my experience with different Aztec codes. They were also confounded and suggested it had to be different headstamped brass, different pieces of brass from different lots...or variations in individual pieces from the same lot - though they didn't really see that being the case from quality brass like Lapua. I showed them that all 400 pieces I have were from the same lot they once echoed some of the comments. I'm not going to put them on blast or share their entire email here, but if anybody wants a PM I'm happy to share what they said. What I will say is that they attest to their product's accuracy and believe it is the brass.

AMP did submit hat they would expect 6 Creedmoor Lapua brass to be much closer to the 0167-0172 range than the readings I got in the low 0150s.

I went ahead and annealed two pieces at 0152, 0167, and 0168. I know "color and appearance" are not indicative of proper annealing....but here were the results..... 0152 came up short?

At this point I know I should probably take five pieces of brass measure neck thickness etc and then record the Aztec code for each. But I really don't want to waste even $6 in brass doing that. Likely, I'll just stick with the 0167 for now.....

FWIW, here are the measurements. I dont see how they would really be different given thwy were all fired in my chamber and should size out to the same. The weights did vary across the 6 within reason.

168.72 / 169.14
168.52 / 168.86
169.60 / 168.72

 

[TheGerman]

Just pick a number in between or averaged.

Stop measuring shit to measure shit to sort, to measure other shit to weigh the shit you measured so you can measure it by weight and height and then remeasure to take out the standard deviation of measurements because the fucking moon may have been tilted.

Just fucking do it.

 

[Senor_Barney]

Just pick a number in between or averaged.

Stop measuring shit to measure shit to sort, to measure other shit to weigh the shit you measured so you can measure it by weight and height and then remeasure to take out the standard deviation of measurements because the fucking moon may have been tilted.

Just fucking do it.

Trust me...my goal was not to measure items just so I could not know the relationship between any of it and my Aztec results. But....I did it because I saw the replies suggesting it and thought I'd appease.

Right or wrong...for now I'm going with 0167

 

[OREGUN]

Interesting. I completely stand by my statement that you are never going to “lot sort” Lapua by any measurement you can do at home and trying to is a huge waste of time. I’d be really curious to know what they said about the potential downstream effects of being ”off“ of the correct Aztec code.…how much matters and how much does it matter?

That conversation that I mentioned, with the custom reloader, started because we were talking about brass consistency across some of the boutique brands and he said Lapua will give him different Aztec codes from the same lot but Alpha brass does not. I’m not an alpha rep and I’ve used Lapua exclusively for ten years or more but it’s another piece of info on this topic. I didn’t ask any of the details regarding how much variability or what he does about it.

 

[918v]

Update:

I reached out to AMP to share my experience with different Aztec codes. They were also confounded and suggested it had to be different headstamped brass, different pieces of brass from different lots...or variations in individual pieces from the same lot - though they didn't really see that being the case from quality brass like Lapua. I showed them that all 400 pieces I have were from the same lot they once echoed some of the comments. I'm not going to put them on blast or share their entire email here, but if anybody wants a PM I'm happy to share what they said. What I will say is that they attest to their product's accuracy and believe it is the brass.

AMP did submit hat they would expect 6 Creedmoor Lapua brass to be much closer to the 0167-0172 range than the readings I got in the low 0150s.

I went ahead and annealed two pieces at 0152, 0167, and 0168. I know "color and appearance" are not indicative of proper annealing....but here were the results..... 0152 came up short?

At this point I know I should probably take five pieces of brass measure neck thickness etc and then record the Aztec code for each. But I really don't want to waste even $6 in brass doing that. Likely, I'll just stick with the 0167 for now.....

FWIW, here are the measurements. I dont see how they would really be different given thwy were all fired in my chamber and should size out to the same. The weights did vary across the 6 within reason.

168.72 / 169.14
168.52 / 168.86
169.60 / 168.72

View attachment 7994857

View attachment 7994856

And the ones that you already analyzed (and produced different settings) were all 404/468?

 

[918v]

.

Interesting. I completely stand by my statement that you are never going to “lot sort” Lapua by any measurement you can do at home and trying to is a huge waste of time. I’d be really curious to know what they said about the potential downstream effects of being ”off“ of the correct Aztec code.…how much matters and how much does it matter?

That conversation that I mentioned, with the custom reloader, started because we were talking about brass consistency across some of the boutique brands and he said Lapua will give him different Aztec codes from the same lot but Alpha brass does not. I’m not an alpha rep and I’ve used Lapua exclusively for ten years or more but it’s another piece of info on this topic. I didn’t ask any of the details regarding how much variability or what he does about it.

A better question is how the variance affects accuracy and ES/SD.

 

[Senor_Barney]

And the ones that you already analyzed (and produced different settings) were all 404/468?

Likely....

but The ones I analyzed are nuked and dimensions might be off now...probably still sitting in a tray on my bench and I'll grab them.

 

[918v]

Just pick a number in between or averaged.

Stop measuring shit to measure shit to sort, to measure other shit to weigh the shit you measured so you can measure it by weight and height and then remeasure to take out the standard deviation of measurements because the fucking moon may have been tilted.

Just fucking do it.

That’s not very German of you.

 

[918v]

Likely....

but The ones I analyzed are nuked and dimensions might be off now...probably still sitting in a tray on my bench and I'll grab them.

Also, did you dry tumble or wet tumble?

 

[Senor_Barney]

Also, did you dry tumble or wet tumble?

Virgin brass. Fired. Wet Tumbled for 28 minutes without pins. Just Dawn and ~85 cases.

 

[918v]

Virgin brass. Fired. Wet Tumbled for 28 minutes without pins. Just Dawn and ~85 cases.

And you dried the cases before annealing?