Annealing

What is the purpose of annealing? Is it to release energy to facilitate sizing or is it to release energy to facilitate proper "grip" of the bullet?
 
Easy way to think of it is you want consistency in reloading. Annealing 1st gets all your brass to have the same springyness/softness before you force it into the correct size. If they aren't the same softness, your dye will move the brass differently for each piece of brass due to a different amount of arm force required to cam it over and force it into the proper size. Sort of like the difference of hammering a nail into soft wood or hard wood using the same strength hammer blow.
 
Yes, however, LOL. Neck thickness of the brass also affects tension on the bullet so different brands of brass with the same hardness (annealing number) will have different results so don't mix brass.
 
What is the purpose of annealing? Is it to release energy to facilitate sizing or is it to release energy to facilitate proper "grip" of the bullet?
There are multiple processes with multiple end goals. This particular company (AMP) specializes in induction annealing with the goal of annealing the case necks and shoulders to just under 100 HV after every firing. Their opinion is that if annealing is used it should be uniform, consistent, and repeatable - if cases are returned to the same state after each firing then sizing should be more consistent, and if sizing is more consistent then grip on the bullet should be more consistent as well. To serve their end goal of consistency and repeatability the annealing process should be done every firing and loading cycle. Success with their method is somewhat predicated on the assumption that a user's sizing and seating processes move brass in a consistent manner and doesn't introduce any irregularities after annealing. A problem with this method is it depends on uniform neck thicknesses, if someone doesn't follow the instructions on fining the correct case to test there can be inconsistencies.

Other methods either use different methods to get to the same goal, or different methods to achieve different goals. There are a lot of options for annealing.

To follow this logic if it all starts at "150" there would be no need to anneal?
It might start there, but brass hardens at different rates over multiple firing and sizing cycles. Part of AMP's logic is that their machine resets brass to the same point every time no matter what inconsistencies get added during a cycle.

There are counters to that - some guys will anneal only every second or third firing but rely on the brass hardening at a similar rate so that the successive loadings are uniform by lot, if not uniform to the prior loading.

Some people will never anneal and will account for increased hardness over the case life cycle by changing to a smaller bushing in a die.

Some people never anneal at all, never change anything, and get good results. There can be other factors to what makes loads good than just case prep. It all depends on the end-user's goals.

I think that's what gets lost in annealing discussions most times - if two guys have different goals, there are probably good reasons for them to not do the same things. Both can do different things that work better for them.
 
I gave annealing some thought. There are different schools of thought on the effectiveness of annealing. Given some recent thoughts and practices by shooters/loaders far more advanced than me, I took the annealing off my list. I subscribe to the "Keeping it Simple and consistent" approach.
 
I myself come under the category of anneal when the brass gets too springy that I have to readjust the die to get shoulder bump or when I start getting splits in the necks. It makes your brass last longer, and we all know how tough it can be to get brass and how expensive it has gotten. Just one example that comes to mind, I shoot both Lapua and Norma 6BR brass. the Norma brass started splitting after just 3 firings. I annealed it and haven't had a problem since. The Lapua has about 15 firings and I haven't had a problem yet.....so I'll keep shooting it until I do. One thing I will mention is that annealing at the intervals that I do, it does screw up the neck tension from where I tuned my load for the first firing, but seems to be fine after that. The next batch I anneal, I'm going to try running them through the sizer twice before loading to see if that makes it better.
I posted this as a piece of information for the folks that didn't actually understand what happens to the brass when you anneal and then resize. The inspection equipment and procedure is top of the line stuff and being a journeyman machinist with metallurgy and heat treating knowledge, I was a bit impressed.
Not many machine shops have a metallurgy department with equipment to check chemical make up of metals or more than a standard Rockwell hardness tester, let alone tensile test equipment or a variety of other test equipment. It used to tick me off to take piece of material from the foundry, make it into a part either on the lathe or the mill, and then watch them stretch it until it broke in half. I worked in a place that had it's own foundry and designed their own proprietary metals for the manufacture of many of the parts we produced. I was also the sole pattern maker for the company's foundry and got to work with the metallurgists fairly often. Not many people have the opportunity to work in such a diverse environment.....anyway the video impressed me a bit.
 
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What is the purpose of annealing? Is it to release energy to facilitate sizing or is it to release energy to facilitate proper "grip" of the bullet?
It is basically to release that energy in order to prevent the hardness of the brass increasing to the point where cracking or splitting of the necks occurs. It also provides greater consistency in terms of neck tension and bullet seating.
 
Anneal then size. The sizing should be more consistent both case-to-case and firing to first after annealing. But that "should" is highly dependent on how much you're working the brass in general.
So today I just got 300 Lapua Match 223 cases to reform into 20 Tactical. Should I anneal them before starting? Or do Lapua cases come annealed?
 

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