longnkrnch wrote:Do I need to, and if so how often should I anneal my brass?
Annealing is an area we've only skirted around so far. It being discussed more in circles where hyper accuracy and case life loss from repeated, competitive shooting is the arena. From my reading, it also seems to be an issue more akin to bottleneck cartridges, but for the same reason it has come to light here. That being adequate and consistent neck tension. IIRC, WC once said he has gotten up to 20 loads or more without it, so it borders on superfluous in our caliber in terms of case life. I don't know about your brass, but mine gets pretty gnarly long before 20 reloads and admit it or not, we do care about how our brass looks to some extent. If, for no other reason than shooting confidence.
After the past week or two's discussions, I actually embarked upon a small experiment. I took some brass I sidelined due to stab crimp scars (there's that confidence thing again) and I'm talking scars on the inside that refuse to shoot out. Anyway, these cases varied from only 2-fired to 6-fired and their scars varied from worthy of concern to superficial. The thrust of the experiment is to anneal all of them, iron out the scars using an identical process for each, sizing and loading them with no deference to how many times the cases within a group had been fired. I'm looking for both a positive effect upon the internal stab scars and "The Great Equalizer" in terms of neck tension consistency.
I annealed the forward one third of the cases, ran them through the resizing die and since this experiment involves using a taper crimp, I did trim all the cases in this endeavor to +/- .001 as that impacts the degree of taper crimp for the same ram stroke. Subtle, but different. I then set about charging them and seating the three bullet weights I'm pursuing as an added aspect to the experiment. More on that when I get around to the actual Range Report. Anyway, I immediately noticed that the resistance to seating the bullets was less than with a couple of non-annealed cases that had been prepped similarly, resized and included in the process. The second observation was that it took less force to achieve the same degree of taper as measured at the case mouth. Third and I admit that this is a subjective observation, the
sense I got from the feedback of the press handle was that springback when applying the taper crimp (yes, you can tune in to that sensation) was slightly less than with those non-annealed cases I ran at the same time.
None of that should come as a surprise since that's why we anneal in the first place. Whether it translates to lower velocity SD's or tighter groups remains to be seen as I couldn't get to the range Saturday and it is closed today due to the Annual Trophy Trap Shoot. Rest assured that as soon as I do get there, I will report in on my mini-experiment. Mini because it's not a lot of sample base, nor does it involve a current control group, relying rather on historical data I've gotten.
Others no doubt precede me in this experiment and perhaps some of them will wade in with their experiment results.
Stay tuned...
Hoot