Measuring AMP annealing's impact on brass- test design

[marchx]

Here is my idea. I selected 30 pieces of Lapua 6BR brass 4x fired, the same lot, the same initial headspace (up to .0001 inch). Brass was fired each time using 30gr of N140 (0.002gr variance). It was 3x sized using Forster bushing bump die, Co-ax press.

I was tracking each piece of brass beginning with first firing/sizing in terms of the following dimensions:
-headspace
-neck diameter
-length

I measured also velocities of 4th firing for each brass (unfortunately, in some cases Labradar did not record the velocities correctly, but still I have a decent sample)

I was tracking each brass seating process in terms of seating force.
So, for now I have good record of progress of (a) headspace variance, (b) neck diameter variance, (c) seating force variance from 1st to 3rd sizing.
.
I would like to get the selected 30 pieces of 4x fired brass annealed by AMP and continue my tracking process. If AMP makes that much difference there should be:
(a) significant measurable improvement in terms of headspace variance after sizing
(b) decrease in seating force variance, general significant decrease in seating force
(c) decrease of SDs

Summary of the test will be done after recording relevant measurements after first sizing and firing of the whole 30 pieces of AMP-annealed brass. I hope, it may provide evidence in procentual difference AMP annealing makes in reloading.

Yes, it may have been done by others in the past, but as Lenin wrote "Trust, but verify" (Works, Volume 20, Berlin 1971, p. 358).

If any of the members could help me out in getting 30 pieces of brass AMP-annealed, pls PM me.

 

[3Ackleys]

You left out checking the target- it's the only thing that really matters.

 

[6.5 forever]

You left out checking the target- it's the only thing that really matters.

Yup

 

[MagnumW]

Great experiment ! I have an amp but not the 6BR riser needed or I would help you. Hopefully someone annealing 6BR’s will step up.

 

[rijndael]

You left out checking the target- it's the only thing that really matters.

Unless your other goal with annealing is to increase the brass' life, not necessarily for on-target benefits.

 

[jepp2]

(b) decrease in seating force variance, general significant decrease in seating force

Test already done by Eric Cortina including seriously over heating the brass. No difference. Doubt you will see a) or c) change.

My experience regarding variation of case head to datum during sizing is case lube type/application is a much larger factor in variation.

But feel free to run your tests. I have an AMP and would anneal them for you if you purchase the needed pilot (I would return it to you with the brass).

 

[marchx]

You left out checking the target- it's the only thing that really matters.

Thank you for this comment. I would like to clarify. The target (i.e. group size) is intentionally curved out here.
I decided to eliminate the human factor in my test- flinching, wobblying (i.e. shooting technique mistakes), and first and the foremost- the wind. Unlike Lou Murdica, I do not own a tunnel and cannot get rid of one of the most important variables- i.e. the wind on a given day.

I think that SD and velocity is an objective measurable evidence. Did SDs decrease and if so how much?

 

[marchx]

Test already done by Eric Cortina including seriously over heating the brass. No difference. Doubt you will see a) or c) change.

My experience regarding variation of case head to datum during sizing is case lube type/application is a much larger factor in variation.

But feel free to run your tests. I have an AMP and would anneal them for you if you purchase the needed pilot (I would return it to you with the brass).

My next test would be to verify the Cortina test, i.e. measure the difference in torch annealing.

Lou Murdica's famous opinion: "either use AMP or do not anneal at all".

 

[ShtrRdy]

I still think you need to include target results.

Before having them annealed fire six 5-shot groups as a baseline. Hopefully you have enough of the same lots of primers, powder, and bullets to do this gwice.

How do you measure 0.002 grain variation?

 

[BoydAllen]

My next test would be to verify the Cortina test, i.e. measure the difference in torch annealing.

Lou Murdica's famous opinion: "either use AMP or do not anneal at all".

Friends have fully met their goals with flame annealing. In one case it was to reduce variance in shoulder bump for a couple of magnum calibers without changing the cases suitability for use in magazine fed hunting rifles with heavy bullets, or ruining tune. Mission accomplished. The other case was a friend who was seeing more variation in seating force than he liked using .223 Lapua brass in a very nice varmint rifle. Using very simple equipment he was able to fix the problem. Both took place before the AMP annealer hit the market. IMO neither would have spent the money if it had been available , or for that matter seen appreciable improvement over their flame processes, given their applications. Lou has a tunnel, and with that the ability to see effects that for the rest of us probably get lost in conditions, shooting outdoors.

 

[marchx]

@BoydAllen I agree with you. On the other hand:

Trust, but verify - Wikipedia

en.wikipedia.org

 

[marchx]

I still think you need to include target results.

Before having them annealed fire six 5-shot groups as a baseline. Hopefully you have enough of the same lots of primers, powder, and bullets to do this gwice.

How do you measure 0.002 grain variation?

sorry. 0.02gr. One kernel of VVN140 weights on average 0.02gr, sometimes 0.01gr. I check every powder charge with 2 lab scales, so there should be zero variance, but I think it's safe to assume 0.02gr variance.

 

[CharlieNC]

You are describing a one point in time evaluation, and why 4X fired? To me a proper evaluation would involve splitting the brass into two segments when new, and tracking the comparison throughout the total life of the brass (which may be affected as well) on annealed every time vs not.

 

[marchx]

@CharlieNC the test you are suggesting is simply different by design. I do not consider "point in time evaluation" as you put it improper. It's designed to measure the difference amp annealing makes on a given population of brass. Everything else in the equation remains the same- reloading process, powder charge, bullet. The only thing that changes is parameters of brass hardness. I do not care for brass life- what interests me is the impact on e.g. Shoulder bump variance, neck tension and las but not least velocity variance.

 

[762plinker]

Thank you for this comment. I would like to clarify. The target (i.e. group size) is intentionally curved out here.
I decided to eliminate the human factor in my test- flinching, wobblying (i.e. shooting technique mistakes), and first and the foremost- the wind. Unlike Lou Murdica, I do not own a tunnel and cannot get rid of one of the most important variables- i.e. the wind on a given day.

I think that SD and velocity is an objective measurable evidence. Did SDs decrease and if so how much?

not..just hoping and guessing...only targets count.
IMHO just a waste of time and money

 

[RegionRat]

A couple of things to keep in mind.

If you will want n=30, then send 31 because the AMP will burn one to get the optimal program.

It is probably good enough to use a similar setting from that brand of 6 BR brass, but if you want it done right you should go ahead and send an extra to let the AMP run the calibration program for this brass.

Also... In research and science, there is a possible pitfall with OFAT (One Factor at a Time) testing.

In so many words, if your current best recipe is based on your current non-AMP process, it is possible it may need re-optimization due to the change. One change to a complex system may require a re-tune of the other parameters in order to achieve an optimum due to one factor changing.

If your current velocity stats are dependent on the cold work state of your necks, it is possible you will need a small change in neck tension or recipe to match them with annealed necks. or it may not. Like I said, a possible pitfall, not a guarantee, of drawing conclusions from one change at a time.

Good Luck and have fun. YMMV

 

[heckrb]

I agree what ultimately matters is target results on paper. Thats the end goal of everything. The problem is that it’s incredibly tough to control all the variables and eliminate the noise from the results. How could you guarantee you exactly duplicate all the parameters from the first group test? Assuming you can make the ammo the exact same as last time you still have Environmental conditions, barrel conditions, shooting position, etc. You can’t replicate without a huge sample size to encompass all these factors.

What you can quantify is changes in shoulder bump, neck tension, and velocity sd, exactly like he is proposing. Now all of these things may or may not affect group size, who knows, if you can even resolve the difference in your testing. It’s a valid first step though I think.

 

[Ccrider]

Despite what some say, changing the amount of neck tension alone can affect es and sd. Annealing changes the amount of neck tension.

Also, rifle tune effects es and sd standing alone from just neck tension. All of these things seem to work together to give you es and sd. Change one and you will likely have to change the others to get back to optimal es and Ed.

Generally, optical Ed and es is not necessarily the best shooting load.

 

[Keith Glasscock]

I'm glad to see shooters verifying the testing they see on YouTube! I encourage it. Without digging into the quality of some of the "testing" presented there, I will say that a lot of it looks pretty bad from a scientific standpoint.

For me, it has been a year of learning/teaching about sample sizes. One thing I do know is that 120 total sizing/shooting observations, over 4 independent conditions, will NOT show anything that even resembles the truth. Take this from a guy that shoots 100+ shot strings to start to understand his ES/SD.

As an aside, I've found that a) depends more on the press and technique than the annealing, and c) is really unlikely and dependent on the specific load attributes before the test.

Like others, I know that the control condition (un-annealed brass) must be included in the testing in order to accurately characterize any observations.

Good luck, and good testing!