Annealing necks ...good thing or bad thing?

[argh]

Guys, if you want a slower motor, try a microwave turntable motor. Ntoe that its 240V though Only wire them up if you know what you are doing.

Most microwave motors range from 2 to 6RPM, but the best thing is that you can find them dumped in every Council cleanup. I have made up one of the anealers in Phils post, and have used microwave motors for fishing rod building drying lathes for years.

Cheers
Adrian

[DenisA]

Hi All,

I bought some 700 deg F Tempilaq and had a play tonight. Thought I'd post up some pics incase anyones interested.

I'm using BBQ gas, a burnzomatic torch and old .284 Lapua brass..

I've written my annealing time in seconds 1 1000, 2 1000, 3 1000 etc at the bottom of each case.

I went from under cooked to overcooked to see the extremes. All cases were air cooled.

Note that the specified temp is reached when the Tempilaq liquifies.

Looking at the pics you can see that 4 and 6 still show clear paint in the neck..... under done
8 and 10 show charred paint in the neck but the Tempilaq still has body............ getting there
12 is the point that the Tempilaq liquifies inside the neck.
Interesting to see that even overcooked with BBQ gas, 16 and 18 still havent annealed the bulk of the body or anywhere near the head.

[williada]

Denis that is a great display. Perhaps I might run with 650 degree. I like the look of 8-10. David.

[DenisA]

Denis that is a great display. Perhaps I might run with 650 degree. I like the look of 8-10. David.

Thanks David. It's by no means technical or comprehnsive but I thought it was worth posting to this thread. It's always good to get other peoples opinions on things too. A picture tells 1000 words and I might have missed 500 of them.

Do you think the 700's too hot or are you accounting for heat soak?

[williada]

Hi Denis, maybe just a tad too warm and yes the heat soak tends to linger longer if your timing is not flash. You can ruin more cases by overheating when you lose concentration. So its insurance. Irrespective of 700 hundred degree Tempilaq, the 8 and 10 second look good. I don't like to anneal too far down the body because my focus is the junction of the neck and shoulder when bumping back .0005". Edit: that's 1/2 thou. I actually think its more important to place the right tension on the barrel action threads and proper annealing is critical to this. So when I work harden the neck internally, a couple of times with that Sinclair dye, I'm not really working the shoulder. I then bump the shoulder. Other people have focussed on the neck. Don't underestimate the role the shoulder plays too. Careful annealing has to be done in the situation where necks have been turned down. Always heat the thickest part first.

Of course, I prefer to leave the body to sort out its own spring back. A lot of the problem with brass is that the resizing dies don't match the chamber. If the brass is worked less with tighter tolerances, then the annealing is not so critical.

Assuming cases are not annealed, then the second firing is loaded with a tad less powder to obtain the previous velocity as the case has not expanded sufficiently because spring back can be greater. Usually by the third and forth firings the cases are approaching full capacity. Thereafter they can be touched up with annealing to regulate the headspace and the necks. For those people that weigh cases or trim then a 4th firing is a logical place to check everything and especially if you are going to volume sort.

David.

[bartman007]

Irrespective of 700 hundred degree Tempilaq, the 8 and 10 second look good. I don't like to anneal too far down the body

Dennis,

A good guide would be to look at brand new Lapua brass, and view the discoloration at the neck. You will see how much it extends down the body of the case.

If you match what the manufacturers are doing, you can't go too wrong.

I agree with David's comment about cases 8 and 10 as they closely match my brand new Lapua cases.

Looks like I might have to make one of these annealing machines myself, when I get time

Another excellent comment from David is about the work hardening of the necks again, to gain that consistency in neck tension.

[DenisA]

My only reservation about 8 and 10 WAS that the Tempilaq inside the neck, which is shielded from the flame hasn't quite liquified yet.
The temilaq that is subject to the flame on the outside of case 12 still hasn't liquified but the Tempilaq inside the neck has.
In my mind it makes sence that across a said batch, slightly under annealed cases would be less consistent than cases that have been annealed to the higher end of the safe spectrum and therefore, based on this test, I thought that 12 was looking best................ until Davids advice.

[bushtick]

metal guru's say 650 degs is the annealing point for brass they suggest 750 deg templaq for necks and 400 deg templaq for the base to protect the brass. keeping heat as close to shoulder as possible .I think annealing frequency could be worked on calibre and the amount of neck clearance , quality of brass. just my thought

[williada]

Denis, there is nothing wrong with 700 Tempilaq as its all a question of dwell time unless you make a fancy machine that times it exactly. I spin my brass in an upside down drill press using a stop watch. So maybe I dwell a bit longer at 650 degrees f as I swing the flame away in reaction to the time. Maybe I should post some pictures. The timing was based on Tempilaq placed on the inside of the neck so it is not corrupted by the flame. I found that as soon as it changes the critical temperature has been reached. That is what has happened in cases run at 8 and ten seconds in your examples and your case as Mike has noticed has not annealed too far into the body which is desirable. While the case brass anneals at 650 to 700 degrees f., it actually starts changing form at about 460f. Some people place 450 Tempilaq on the body to ensure that it does not get annealed. I place my flame in the centre of the shoulder which is usually the headspace reference mark so its the hottest part in the procedure which allows the heat to be conducted into the neck. This is necessary if your cases have been turned and are thinner than the body. You don't want thin necks being overcooked yet have an underdone shoulder. The upper range is 800 f, so if turned necks go past this there are problems because the necks are too soft or mushy or rubbery and tend to deform on bullet seating sometimes swelling.

Alternatively, you could use a lead bath. Lead melts at 621.5 f and you can heat it up to and hold it at the desired temperature and dip cases up to the shoulder for the required dwell time and your Tempilaq readings will be accurate. In this case, just dab a bit of Tempilaq on the outside at the shoulder body junction. It is necessary have removed all primers and the cases must be dry unless you want to wear the lead. Make sure this is done outside for ventilation and you are gloved and masked up. Lead is a poison and so are the fumes. An old fashioned method but reliable.

As I said before, the 650f anneal has less chance of ruining the required stiffness in the body and the shoulder tension is about right for the bump. So I imagine, the shoulder could be a tad over 650f by the time the heat reaches the desired neck temperature. David.

[plumbs7]

Wow this thread is still going ? Thanks to all of the contributions ! GS