New AMP Annealer

[RC20]

RC20,

I'm curious why the paint and stick results would be any different? In the past I actually filed some dust off the stick and mixed it with alcohol to apply it in order not to have to pre-warm the case to get a smooth application. Seemed to work fine, too.

If you feel unsure about the liquids, you can bracket them with several temperatures at a time. See which ones melt simultaneously with the stick you like.

Jeephammer feels the liquid have metal particles in the liquid. I agree.

If I get the time I will pursue that with Templiq, but the difference is significant and I found it unreliable.

Crayons are not the best answer either, you have to catch the case at max heat and then you have the cool off factor as well as the cooling affect of the crayon.

Not an issue on dense metals, but thin brass, I don't think its spot accurate.

Ergo, I have taken a creep up approach. I find the rough timing, push it over the edge to where I get a minimal glow (dar4k room) drop that down, significant time wise, then cross check with a crayon.

It seems to work. I believe its bringing them in a bit below ideal temperature but I am not worried about that , I am annealing often enough that no cracks yet.

My take is this is a very hard area to get provable results short of quasi factory setup like Jeephmmaer has. Therein lies the rub, you need that to actually prove your results with a quality control process if you want to say 100% your efforts are there.

Mine are good enough for amateur work.

 

[hounddawg]

Mine are good enough for amateur work.

I called it good enough when I was pretty sure my ammo could outshoot my abilities

 

[Unclenick]

Jugornot,

Congrats on the lower SD's. That's the result you get when seating primers correctly and if you handle the cartridges so the powder position in the cases is same for every shot.

The next thing to learn is if your POI and velocity sweet spots coincide. Either the Audette Ladder (under Incremental Load Development) or Dan Newberry's OCW round robin can tell you that.


RC20 and Jeephammer,

Have either of you guys applied same-temperature crayon and liquid to a case and verified they turn at the same time in a flame, but not at the same time in an induction annealer? Or at the same time when heated slowly, but not when heated quickly? Since these compounds are basically high temperature waxes, and since, even if there were metal particles in them, the particles would be small and separated by insulting wax and therefore unable to carry eddy currents to make heat (insulated particulate composition is how eddy current heating losses in the ferrite core materials are prevented), it should make no difference other than to thermal conductivity of the material. What I can imagine, without conducting the test myself, is that the dried liquid and crayon would have differing intimacy of contact with the metal surface and differing thermal conductivity. This would result in different response speeds, thus appearing to turn at different temperatures during fast heating when one of them is actually just responding faster than the other can do.

If there is actually some difference, just grind up some Tempilstik and mix into a slurry with alcohol and paint on. Works fine.

 

[Metal god]

I know they are only 3 shot groups, but they are the lowest spreads and deviation I have ever shot.

Yep 3 shots mean nothing really . I'd say the consistency of your rifle hold will effect your ES/SD more then 1 or 2 tenths grains of powder .

I did a test a few years ago ( data not in front of me ) that showed changing how you hold the rifle effects ES/SD significantly .The rifle was a 308 Savage model 10 . Now these were only 5 shot test but were using the exact same ammo I loaded . They were all the same components loaded at the same time , stored and transported in the same way from bench to range .

I ran two test with both test using a front and rear bag as the rests . First test was holding the rifle VERY tight and hard into my shoulder . That test produced something like an ES 30 with a SD 17 . The second test was done with virtually no hold or pressure on the rifle and letting it freely recoil . Just my finger on the trigger and my arms and body around the rifle but not touching to control the rifle from flying off the table . That second test ( using the exact same ammo ) just 15 min later had a ES of 12 and a SD of 5 . This was done with a 14lb rifle that has a muzzle brake so it was pretty easy to control on the free recoil part of the test

I'll add this was through a well fouled barrel of at least 50 rounds and I let the barrel cool 15 min before the second test . I used an inferred thermometer and believe the barrel temp differences were 3 degrees .

The reason I did the test was for a couple reasons but the main one was I was consistently having my first shots in groups shoot 10 to 15 fps slower then the next 4 and that was blowing up my ES/SD numbers . It was recommended to me by BartB that my rifle hold was the problem . At first I did not even give it a thought but one day I went ahead and ran the test just to see how much rifle hold effects velocity . Boy was I surprised , I'll add that the test with the tight grip also averaged a higher velocity as well . It was not much but was recordable .

This test changed how I shoot , really because how you hold the rifle is a huge factor on your shooting .

 

[RC20]

While its no nearly as fact driven as MG, I had one of my best shooting days in come really cold weather.

Ie. lots of layers and easier to let the rifle free recoil.

Bart B made that observation a number of time and I agree, consistent hold is one of the bit key item.

 

[RC20]

Unclenick:

This is not being argumentative let alone for argumentative sake. Solid data which I have learned to pay attention to (from my work)


I have two temperature of the paint on Templiaq, 750 and 800.

Templiaq sent me two more when I had issues with the 750 melting before the 800.

Same result. Timing wise with a very precision setup for the case in the coil same height, same mfg cases.

I am not a metallurgist, I do have a lot of mechanical experience as well as tech work with electronics, relay logic, power systems.

When I have encountered a disagreement in data, I go back and check and test.

When it holds consistent as this did I won't use it (maybe as a ballpark guide).

The Annie is settable down to tenth of a second, the 800 was clearly taking more time to melt than the 750.

I eliminated error as best I could with an entire different bottles of both the 750 and 800.

So its a bit of Kentucky windage and shooting low rather than high.

I have made more than one mistake in my work when I did not believe the data I collected and went off in the wrong direction. I pay attention to those details as they are always very relevant.

I have had a few of times of the factory techs telling me I was wrong, but when the evidence says otherwise, you throw the mfg out.

Happy to get ideas, but at this point I don't know where to go.

 

[Unclenick]

Templiaq sent me two more when I had issues with the 750 melting before the 800.

I am not wanting to be argumentative, either, I am just trying to understand the problem and the difference between crayons and liquid form behavior. You say the 750 liquid melted first, but isn't that what you expect? As you heat something up to 800 you will pass through 750 first. Or are you saying the 800 melted first?

Also, as the temperature increases, heat is being lost to air faster, slowing the rate of temperature increase, so you'd expect the 800 to melt second and to take longer to melt. But if it didn't go that way, you have an interesting puzzle on your hands.

One factor with all PCM's (phase change materials; including waxes) that go from solid to liquid (melting or thawing) or from liquid to gas (boiling or evaporating) or from solid to gas (sublimation) is that they have not only to hit certain temperatures to change phase, but to will tend to stall the rise in temperature while they absorb enough heat to complete the change of phase (in this case from solid to liquid). The amount of heat such a material has to absorb to make the change is called its enthalpy of fusion. A pound of ice, for example increased in temperature about 2°F for each Btu of heat absorbed, then at 32°F it has to absorb about 143.5 Btu's to convert to liquid phase, and then, in liquid form, it heats 1°F/Btu absorbed. If you measure the temperature of the center of an ice cube in a glass sitting in room temperature air, it first rises to 32°F, stays there until it melts, then the newly melted water temperature starts to rise again, but only half as fast just above the melting point as the ice was doing just before reaching the melting point.

Waxes are PCM's, too, but often not highly pure. Alkenes (paraffins) will need anywhere from about 40 to 100 Btu/lb to melt, depending on the purity of the carbon chain lengths in the material. And, in impure form, instead of holding at exactly one temperature as they melt, they melt over a range of temperatures called the slush zone. So it wouldn't surprise me if a crayon labeled 750 actually started melting at 730 and didn't finish until 750, or some such range. It wouldn't surprise me if, due to differences in purity or in impurities, such as the coloring material, one had a lower enthalpy of fusion than another, affecting how long they needed to be exposed to a given temperature to melt. If you let two waxes come into contact, you will get a mix at the interface that has an even wider slush zone and may confuse the exact melting point.

Lots of trouble to get into, and because of the timing issues for different enthalpies or for the exact compositions having different thermal effusivities (a measure of ease of heat transfer to the wax from the metal surface it is on) or different thermal diffusivities (a measure of the ease of heat spreads within a material), it is possible to have the two appear to work perfectly if you heat the work very gradually, but appear to be off or even reversed if you heat the work quickly.

If the problem is with the latter, then the indicators may simply be unsuitable for any but slow methods of case neck heating. It might then be better to calibrate by coating each neck with candle soot to maximize IR emissivity (a lot of 'x'-sivities in this topic) and use an IR thermometer.

On top of all that, since the metal has to change its grain structure and some of those changes are time-dependent at any given temperature, I'm not convinced we don't need to hit a higher temperature when heating at very high power for 0.25 seconds than we do when heating for 2.5 seconds with less power, and I don't know what those temperature differences might be. And they may change with the alloy being used. I think that's what the AMP annealing people are getting at. Their finding they need different times for different amounts of brass mass and different alloys and find measuring the hardness they get the only way to be consistent with the results.

As a friend of mine like's to say, "Oy vey Maria!"

 

[RC20]

Yes, the 800 deg melts before the 750.

A good 2/10 of a second.

Settings are in the 2.1 second range so its a significant percentage the wrong way.

 

[jugornot]

Ok, so I was checking cases last night. 46 rounds was probably 50 to begin with. 30 Lake City 14 and 16 Lake City 12. The 14 measured 1.626 to 1.6305. The 12 all measured between 1.6215 and 1.622. These were all shot with my DPMS Gen II 308. This mirrors my earlier measurements in a previous post. This came to light because my annealing machine has different settings for different brass from Lake City. I used to segregate cases only by Lapua and everything else. If nothing else this convinces me of the necessity of sorting brass. My Lapua unfired measures 1.621 to 1.622. When I resize it all comes down to 1.6205 to 1.621. I am resizing the 14 by .o10 to .005. The 12's I am not changing much at all. There is some sizing just no bump back. This was consistent over all the cases. I came up with the setup I am using by using the Lapua and in effect going back to stock length. On one further case I measured before body sizing I measured total length and it grew by .003" after resizing. Before annealing I would have trouble bumping these cases back to where I wanted.

Ok now the question Is the 14 expanding to my chamber and the 12 not expanding? The dies are doing their job. I feel the 14 brass is definitely being overworked. I got the brass as cheap pulled brass primered and never fired. I thought Lake City was ok. Anyone got an explanation?