Originally Posted By: tnshootistOriginally Posted By: msincOriginally Posted By: robsSome real good info on this at Accurate Shooter.com
Yep, there is a lot of info on this subject, but I am not so sure how much of it is all that good. Much of it does not bear out to be true based on my 30 some years of doing this. I am no expert and don't claim to be, nor am I a metallurgist...but I know what I have experienced to be true.
Every post regarding "How to" questions get well in excess of usually 30 or more answers. Seems everyone knows how to do it and is an expert...most of them can even tell you how to build a working annealing machine!!!
Funny thing is, I posted asking how they knew what they were doing to anneal was working and just what it did for them and I got two {2} replies with kind of generic answers.
As to the color thing...I know as a machinist by trade that the color metal turns when heated often has more to do with what was on it then temperature differences. When I worked in an automotive machine shop the quickest way to install new pistons on connecting rods was to heat the eye of the rod in a Sunnen "rod furnace" and when it got hot enough to expand, slip the wrist pin thru. It immediately locks when they cool off and you are good to go....except that the wrist pin end of the rod turned a bright blue and the customers believed this would weaken the rod. It was a micro thin layer of blue colored oxide that we would remove very quickly with naval jelly. The customer never seen it and all was happy. Point being, forget about the color of one brand or somebody else's annealing work, it doesn't mean much.
Just like the temperature...I ask what temp and WHY and not a single answer was posted...yet everyone can tell you an exact temperature to anneal to. What B.S.
So,please share the correct temp or the correct method please. I have been trying to sort out the chaff for some time and the best I can do is with the Tempilac. I am not fully confident in that because all I know is the manufacturer says it melts at 750 and 750 is supposed to be a good temp. I can't prove or disprove anything and would like to know more.
Well, again...I am no "expert" or metallurgist by a long shot, but I will certainly share my experience with annealing. No doubt the real experts will be along shortly to shoot holes in this post, but this is what I have found to be true:
In 1991 I got a lathe and so quickly after that I decided to build my own "custom" rifle. I did up a 700 in 308 with an HS Precision stock and a 28" 1 in 10 polygonal rifled barrel. On top was the then "ultimate" in a long range scope...the Leupold MarK 4 M1 mil-dot from Premier Reticles. A Tubb speedlock and Timney trigger completed the build.
The rifle shot very well, I was happy. It would shag a hole at 100 yards. At that time I used to shoot a lot with a fellow gunsmith friend of mine and together we had just about everything we needed to build and blue guns, light machine work, reloading, etc. He had a chronograph, one of those Oehler's that printed out a little sheet of paper with every shot. All I really watched on the thing was the velocity. I was then too ignorant to know any better. I remember him remarking about the standard deviation and extreme spread, and how he just couldn't seem to get one or the other below a certain number he thought it should be. I was shooting better groups than I ever thought I would so I didn't give it much importance. Then the groups opened up and the velocity was like 50 fps different between shots.
About this time I noticed that when I would size the brass I was getting a chirp noise when the case passed back over the expander. I tried everything, even grease in the case neck, but it still felt bad. I knew something wasn't right so I referred back to a book I had titled "Modern Handloading" by George C. Nonte, Jr. He had this section on annealing. Seemed simple enough, he stood cases up in a pan of water, heated them until the neck was "dull cherry red" and tipped them over. This was done one case at a time. At the time I didn't assign much importance to this operation, but I gave it a try and immediately noticed not only was the chirp gone but passing over the expander ball felt like it was greased up slick.
Next time we got together for a shoot I got off about 5 rounds and my buddy Joe looked at the chronograph and went crazy..."whoa, what did you do to these loads???" "How can this be???", etc. There was only 5 feet per second difference in velocity between all 5 rounds. The only thing I did different was the annealing. There was less than 10 fps at the end of the shooting session.
Since then I always anneal my cases, not every loading, but about every 4th or 5th time. Here is what I have found, I use a cordless screwdriver with a 3/8" socket drive tip and a deep well socket that the case can set in. I spin the cases about a slow medium speed and heat the neck with a propane torch until they just start to glow that dull cherry red with the lights down dim. Then tip it out and into a container of water to quench. That's really it, I have never made any attempt to check or verify temperature. I have barely heated some cases testing and they didn't get as soft as they do this way. You must see at least that dull cherry red when they very first start to glow and the lights are dim.
I have also over heated some cases just to see what would happen...heated to the point that they scorched the surface and discolored black. This was a heat change that would not polish off in a vibratory cleaner, no matter how much a ran them. And guess what??? They loaded and shot just fine. Those "overheated" cases were glowing bright orange for several seconds on purpose and some are still in use. I was able to polish the black off the case necks with a buffing wheel and they returned to looking like normal brass. Based on what I have done annealing I believe that brass is easy to anneal and temperature is no where near as important as some would make it out to be. That's not to say that you shouldn't still try to get them as consistent as possible, just that the great lengths guys are going to doesn't appear to be necessary. If you were trying to get 6061 alloy to T-6 heat treat that is more exact, if you are shooting for a certain Rockwell hardness on 154CM for a space shuttle part you probably need computer controlled equipment, but just to soften brass a simple torch, drill, bucket of water and darkened room are all you need.
I find that the differences in color of the neck/shoulder area are more affected by whats on the metal when you start way more than temperature. On fresh STM tumbled cases they are clean looking and almost have a pink hue to them...if I get in a hurry and don't get all the sizing lube off they will develop that pretty rainbow with blues down near the non-annealed part of the case. Either way though I still see the same results on the chronograph regardless of the color or the amount or time of the heat applied. I have not had a single case fail yet, but I will say that old cases {30 years old or better} that are more air hardened {over time} sometimes cannot be brought back from the dead as easily as work hardened brass.
Maybe another way to say it is that if when I took a given number of cases, heated them as above to dull cherry red and immediately quenched, then took that number again and heated to where they were just starting to show a little orange held them there for 10 seconds and dropped them, then took some and turned them bright orange and set them on the counter to cool {not quenching at all} they all annealed, got soft and showed the same results on the chrono.
Bottom line, what I am seeing and testing just doesn't support all this exact science, certain exact absolute temperature, heat time just right, "rocket science" quench in magic voodoo liquid to get brass cases dead soft.
Heat 'em till they just start to glow, drop 'em in the water and go shooting. Looking back, I didn't even spin those first cases, I held them with pliers and scorched a few, but they still worked fine.
I continue to be amazed at how many folks have all the answers on "how to" and "why do it", but none can tell you if it actually worked or accomplished anything and how they knew if it did.
Hope this helps someone, best of luck and good shooting!!!!
Edit: I guess I should add that I get asked a lot the magic question..."all other things being correct, what can I expect to gain by annealing my cases??" Well, maybe not much but enough. If you have a great shooting rifle {and caliber} to start with the gain wont be a lot. But there will be some tangible gain. At the very least your cases will last longer, but they will perform better too. Take some cases that are work hardened, chirping on the expander and load them, then also load the exact same load with annealed brass and shoot them in the exact same rifle you will see better groups and way more consistent velocity across the board. I cannot tell why hardened necks cause velocities to go erratic, you would think if the brass was all a certain hardness they would gain velocity all the same, but they do not. Either bullet tension does strange things to a given load or brass work hardens differently with each case even though the cases have been "down the same road" so to speak. Maybe something new to start testing???