Discussion in 'Reloading Forum (All Calibers)' started by willbas, Oct 4, 2019.
Now more money to spend on
The L.E. WIlson seating dies rock.
I am currently addressing the seating load problem. I annealed a bunch of 6BR brass, and the force to seat went WAY up. The annealing process ( induction) burnt all of the carbon out of the necks,( which I believe acts a bit like a lube) and the results are apparent on the target at 100 yards. The unannealed brass, which was loaded at a prior time is shooting much smaller groups.
I have ordered some Imperial Dry neck lube and when it arrives later today, I will try loading some annealed brass, with the inside of the neck lubed, to see how it "feels" then test it at the range to compare how it groups.
Strong effect from just a little nylon brush, wouldn’t you say?
The tribology of the neck to bullet has always been a worry for me.
Keeping chamfer burrs and friction coefficients the same is just as interesting as keeping the pressure of neck tension the same.
It would be good to have those results written up. I’ve had to re-watch it several times to try and get the gist of what each sample was and how it played. I’m not following his explanation of why the un-annealed sample was so much lower than the annealed, but a single run of each isn’t enough to get worried about either. Having been in weapon science and tribology for a lifetime gets you used to how cruel Mother Nature can be....
I honestly stopped annealing. it does not help me at all to shoot smaller groups. annealing was supposed to help with neck tension, but it just makes it vary a whole bunch. using the proper neck bushing works better than annealing. See the third round loaded in the video.
I can't till they invent something that will pull the trigger for me. Then I can just sit at home and watch my scores go up
His take was the non annealed brass had more spring back(brass wanted to return to fired diameter after sizing). Which resulted in less neck tension/ lower seating force.
The only time springback would be a problem is when the metal is bent past the elastic deformation phase and is into the plastic deformation. For normal shooting and good that would only occur after the round is fired. The elasticity is the force that holds the bullet in place and elasticity is determined by the chemical makeup of the material and the force of electrons and protons pulling and repelling each other
for my 6mm Creedmoor I use a Redding S bushing die and with a .268 bushing. With Alpha brass on it's 4th sizing the OD of the neck is .268, the neck diameter after seating the bullet is .271. Simply put when that bullet is inserted I am stretching the brass of the neck area .003. Once fired the neck the gas expands the outside of the neck to the walls of the chamber and after springback it measures .273. Once resized the OD should once again be .268. If you suspect that your brass is work hardened to the point where it is affecting neck tension it is a simple matter to test it. Simply measure neck OD, seat a bullet, pull the bullet, then remeasure. The neck OD should be the same as before seating the bullet. That will tell you if the neck is being pushed past the elastic phase and into plastic deformation. If it does not then the brass needs to be annealed and resizing.
Unless I misread what took place there was less force needed to seat the bullet when the carbon was removed. I always thought that the carbon in the neck acted like a lubricant making bullet seating easier thus giving more consistent neck tension.
Pay no attention to actual testing with actual scientific equipment...
Nothing to see here. Move along please.
I’m familiar with Mil-Spec tests, where ammunition was typically crimped and also sealed in the necks. Those set back and pull out forces were part of the performance and quality control testing. It was easier to run with displacement than time base in those days. Our data acquisition systems were not as automated and screen-based when I was involved.
That heavy weapons brass is always virgin and the SPC guys had it down pat. There was very little variation in the process within a batch and they worked hard to make the batch to batch numbers identical. This is a far cry from what we are doing as reloaders and target shooters when we try and re use our brass. The industry tolerated a few of us asking questions more oriented towards our hobby, but they didn’t exactly condone running tests or experiments for hobby purposes either. If it weren’t for the AMU guys working the small arms sniper issues, there would have been no interest in small arms neck tension, tribology, or annealing with respect to reloading at all within the government labs.
It would be great to add the displacement axis to this test in order to eliminate as much of that rig stiffness in those time plots as possible. I’m looking forward to some more methodical tests with better stats in the future.
I would love to see the AMP annealer tested under firing line conditions. The real test of annealing is if it improves the ability of putting holes in paper. Some test tunnel time in regard to accuracy and case life would be nice to see. Until then the physics of how metal reacts to stress has been around for a while now and just bewcasue the metal has a Lapua stamp on it does not alter the laws of nature
It's just merchandising. Nothing new
Look at the season long aggregates to 1000-Benchrest results, and much of what your wanting to see is readily available.
For instance, look at Matt Kline's (@dkhunt14) HV-Gun season aggregates at Williamsport for the last +10 years (CLICK HERE). Matt has been annealing his Norma 300-WSM brass every cycle, basically ever since he started shooting a 300-WSM.
But at the same time you can look at results of others that don't anneal with similar aggregate capability, which proves there is no "law of nature" when it comes to cartridge brass, and that there is no single right way with cartridge brass, as to anneal or not to anneal.
Just my 2-Cents
In my experience, running a nylon brush in and out of the neck of a fired case four times will only take out the loose powder fouling, and does not come anywhere near taking it all out.
Would there be a reason you couldn’t just coat your nylon brush with dry lube and apply it that way? Then you wouldn’t end up with lube on the outside of the neck as well.
What your statement tells me is that annealing has naught to do with accuracy or precision when shooting.
Now compare the elasticity of Annealed Brass to Extra Hard Brass in these links. With the extra hard brass tensile strength is increased by almost 500% and hardness by over 30%. However the elasticity is exactly the same.
AMP has spent a lot of money showing us that annealing using their machine will anneal properly. Kudos for that, there is no doubt in my mind now that buying a AMP will give me the perfect anneal which will increase the ductility of the metal and return the grain size to the annealed state. However any engineer or metallurgist will tell you ductility has absolutely nothing to do with the elasticity of metal which is the property that dictates the neck tension.
If you have a problem with necks splitting then by all means get a AMP, it will cure that problem for you. If you seat a bullet and then pull it and it does not go back to the same dimension it was before seating then the AMP will help neck tension by increasing the yield point so that the metal never reaches plastic deformation stage during the seating process. I don't have either of those problems. You can test your own brass by simply seating a bullet then pulling it to see if the neck springs back to the same dimension it was before being stretched. That simple test will tell you whether you need to anneal or just buy some new brass or if your brass is good to go as is
Tubb has that load cell on his ammunition machine. It is so rare that anyone actually uses data.
If you say so and so won such in such and he does this and that, so it obviously works.
You could sacrifice a live chicken over the ammo and shoot a record and there would be people that would say the chicken sacrifice obviously works...
The new thing is going to be gluing the bullets in to increase the pull force so high the seating force is nullified. This is what the military is already doing.
when the base of that bullet gets hit with a few thousand psi of hot gas I have to wonder exactly how much the seating force comes into play. But then again I am just a rookie F class shooter trying to get a handle on the basics. My experience so far is that .003 compression gives me the most consistent numbers on the chrono. If I ever get into benchrest I will probably end up doing a lot of things that I don't do now. Maybe even get a supply of chickens and sharpen my knife
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