What cartridges are you shooting?with me getting an annealing machine, to expand on the process, in what step of the brass prep should it be completed? And how do you know that you have the right time and heat on the neck of the brass?
How long have you been reloading?
What distances are your practice targets?
What range is your game?
Annealing *will* extend brass life. Done wrong, it will ruin your brass.
I would anticipate that you would have noticed differences in the neck tension as you have reloaded your bottle necked cases. Annealing returns your brass to the crystalline structure some call "soft."
IIRC, there's a very good article on it on this website which discusses the metallurgy.
If you are a "MOA all day" or BR shooter, you may notice the effect of annealing on your targets.
As a reloader with a properly tuned load, you may see the effect in your chrony readings.
I say *may* because it all depends on your technique.
And then there's the wind....
Not written to discourage - annealing is another tunnel in the rabbit hole.
You are asking good questions, but I think it will help to have a greater understanding, and I'd suggest you do more reading.
Otherwise the gear just barbecues brass.