Brass springback over time

[Oldbloke]

I think it's pretty difficult to do that.

 

[Oldbloke]

The point is, that "over annealing" is basically mis information. To over anneal you would need to be on LSD.

There is a HUGE window.

 

[Syncrowave]

Shoulder should be annealed as well as the neck. (Not sure how one could anneal the neck without annealing the shoulder, considering how thermally conductive brass is.) If you keep the flame on the neck / shoulder area, it's pretty easy to observe the color change moving back into the case.

It's back near the head where you want to keep the heat away from. If you ever see the color running back too far, too fast into your case, just drop it into cold water. (Unlike steel, brass does not harden with quenching.)

Over-annealing -- If the brass turns pinkish, that means you drove off the zinc in your brass. Bad juju. (Google: de-zincification.) It also likely means you kept it in the flame long enough to anneal the head. Also bad juju.

 

[DLT]

Shoulder should be annealed as well as the neck. (Not sure how one could anneal the neck without annealing the shoulder, considering how thermally conductive brass is.) If you keep the flame on the neck / shoulder area, it's pretty easy to observe the color change moving back into the case.

It's back near the head where you want to keep the heat away from. If you ever see the color running back too far, too fast into your case, just drop it into cold water. (Unlike steel, brass does not harden with quenching.)

Over-annealing -- If the brass turns pinkish, that means you drove off the zinc in your brass. Bad juju. (Google: de-zincification.) It also likely means you kept it in the flame long enough to anneal the head. Also bad juju.

I don’t believe that

 

[Bottom Fodder]

I don’t anneal and from a long range Benchrest shooters perspective, take this as you will.

I never see neck OD spring back even after a couple months, I burnish the layer of left over carbon with a bore brush just prior to seating to get remarkable seating consistency.
My observations:
Bullet hold variation changes targets, seating depth from shoulder to bullet ogive changes targets but a thousandths of headspace doesn’t seem to make any difference unless the case won’t chamber freely or extract leading forcing a bolt open.

Thanks for posting this,I have experience the same

 

[Webster]

Shoulder should be annealed as well as the neck. (Not sure how one could anneal the neck without annealing the shoulder, considering how thermally conductive brass is.) If you keep the flame on the neck / shoulder area, it's pretty easy to observe the color change moving back into the case.

It's back near the head where you want to keep the heat away from. If you ever see the color running back too far, too fast into your case, just drop it into cold water. (Unlike steel, brass does not harden with quenching.)

Over-annealing -- If the brass turns pinkish, that means you drove off the zinc in your brass. Bad juju. (Google: de-zincification.) It also likely means you kept it in the flame long enough to anneal the head. Also bad juju.

It's impossible to anneal the case head. Pink doesn't mean zinc is being burned off.

From the AMPS website;
I have not seen, experienced or found reference articles that discuss dezincification of brass under heating conditions alone. All avenues point to dezincification in the presence of certain chemicals either on their own or in solutions.

The flame color changing while annealing doesn't indicate over annealing or the Zn being burned off.

 

[Syncrowave]

It's impossible to anneal the case head.

If you get the head (or the body just above the head) to annealing temperature, you will anneal it.

The flame color changing while annealing doesn't indicate over annealing or the Zn being burned off.

When I said "pink," I was referring to the brass (or reduced-zinc matrix that's left of it), not the flame color.

 

[Paddyd]

Thanks JFrank.
It could be im worrying about nothing. As you say, they chamber just fine. And the rifle does shoot great.

I was just surprised and disappointed by the change in shoulder. Given how much time and effort I put into brass prep.

I'll make a few small changes to my process and see if I can stop them spring back.

Forgive me if I missed it, but what brand cases are you using. Some alloys differ quite a bit from brand to brand. I just checked 30 or so Alpha cases and they just never seem to grow. I keep them right in the middle of trim range and after the first trim àt 5 firings. I'm on 12 now and they've only grown between 1 and 2 thou. Some not at all. I believe inconsistencies begin with the quality of the virgin brass and how it is initially fireformed.

 

[Elfster4321]

when sizing once fired lake city 5.56 and especially 7.62 before i annealed, and with the considerable headspace this once fired come with in comparison to my rifle's chamber fireformed, no joke i would need to bump headspace pushing 9 to 10 thousands! and would need to run brass thru the sizing die twice for a consistent headspace bump for my target fireformed headspace. Using my EP 2.0 annealer and now annealing my brass, and I measure to confirm, i only need to run them thru once... i anneal every time with the reload with the EP 2.0 annealer which is sooooo easy to use especially when going from casing to casing without having to add or remove any parts and its only $239.00