Fix for buckled shoulders

Good job on recovering the case but obviously something is wrong. My initial guess would be over annealing of the case from the factory.

Secondary to that have you mic'd the brass neck thickness to confirm it is in spec?
 
Nice job. Did you plug the case neck when you grabbed it with the puller die?
With my first try, before annealing, I left the bullet seated. With the second try after annealing, I decided to try without plugging the neck and if that failed then I would try again with the neck plugged. As it turned out I was able to get enough grip on the neck without a plug to be successful.
 
Did you reanneal after getting the buckle out?

Also, did you determine why it was buckling?
I annealed just the neck and not the shoulder after getting the buckle out. Yes, the case buckling was due to to much neck tension. The necks on Peterson brass in much thicker than on other brass I have reloaded.
 
So to be clear, you bought new brass, and with no annealing and no sizing you loaded up and seated bullets to run into this?
Did you do ANYTHING to cause this?
This was virgin brass. Before reloading I weighed and measured the brass and chamfered the necks. After the having 2 cases buckle I then ran the neck expander button from my die though them. The buckling was caused by excessive neck tension due to the thickness of the Peterson brass.
 
Your seating die was adjusted too far down, Backing it off would have solved your problem. Your brass was annealed before it left the factory.
No, my seating die was adjusted properly. I can run a case all the way into the seating die without buckling and without any felt ram resistance. Of the 20 I seated, only 5 buckled and it was due to too much neck tension. The bullet would seat until the base of the bullet reached the neck/shoulder junction and then buckle. I had never worked with Peterson brass and because of the thickness of their brass, there was just way too much tension and the shoulders gave way. I have no doubt that the brass was properly annealed by Peterson. This is in no way a slam on their brass, it is outstanding. I just needed to make a change in my technique to account for their superior quality, thick brass. The need for me to anneal the brass was to eliminate the work hardening I induced by buckling the shoulder.
 
Good job on recovering the case but obviously something is wrong. My initial guess would be over annealing of the case from the factory.

Secondary to that have you mic'd the brass neck thickness to confirm it is in spec?
Yes, before reloading the brass was weighed and measured. Neck thickness was very consistent, all at 0.015". Weight of the 200 cases I received had an extreme spread of 2 grains, with 100 cases having an extreme spread of 0.4 grains. The brass is top quality!
 
Here's another thought for your buckled cases ! I've used the RCBS collet bullet puller going up 1 cal and tighten down over the brass neck! This works real well with the bullet in place ! Once the case is drawn out go back to cal and pull the bullet ! Then anneal and reset bullet to Proper OAL
 
Here's another thought for your buckled cases ! I've used the RCBS collet bullet puller going up 1 cal and tighten down over the brass neck! This works real well with the bullet in place ! Once the case is drawn out go back to cal and pull the bullet ! Then anneal and reset bullet to Proper OAL
I tried to do this first, but was unable to generate enough force with the ram to "pull" out the buckle. So I disassembled the round and annealed the neck and shoulder. The buckle then pulled out very easily.
 
Yes, the case buckling was due to to much neck tension.
Explain this comment, since it doesn't make sense to me. If the mandrel inside the neck correctly sizes the neck during full sizing or neck sizing, then the tension should be correct. After sizing, the bullet seating die only contacts the bullet ogive and pushes the bullet into the already sized neck. In my reasoning, the mandrel sets the tension during the up-stroke sizing. Down-stroke pushes neck and shoulder smaller and up-stroke expands neck and sets neck tension. Understand crimping would affect tension during bullet seating, but just seating a bullet without a crimp should have the correct tension set by the mandrel during up-stroke sizing.
 
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Explain this comment, since it doesn't make sense to me. If the mandrel inside the neck correctly sizes the neck during full sizing or neck sizing, then the tension should be correct. After sizing, the bullet seating die only contacts the bullet ogive and pushes the bullet into the already sized neck. In my reasoning, the mandrel sets the tension during the up-stroke sizing. Down-stroke pushes neck and shoulder smaller and up-stroke expands neck and sets neck tension. Understand crimping would affect tension during bullet seating, but just seating a bullet without a crimp should have the correct tension set by the mandrel during up-stroke sizing.
This is virgin brass that I never ran through a sizing die. Initially the only case prep I did was to chamfer/deburr the necks. After I buckled two cases, I checked for the cause and discovered the necks were too small (ID measured 0.289). I then ran my remaining unloaded cases into my sizing die just enough to push the mandrel through the neck to open it up.

The mandrel on my die measures 0.2625. Due to the thickness of the brass there is more spring back in the brass than with the Hornady brass I have previously loaded, and more tension at the same neck diameter. My solution has been to run the cases through the mandrel multiple times until it goes through effortlessly and then apply some hBN to the inside of the case necks to act as a dry lube. This has resolved the problem.
 
How did the bullets look? Were they deformed from the increased pressure on the seating stem?

When I was trying to form Peterson 270 Win brass to 6.5 Sherman, I ran into neck thickness issues as well. However, I didn't have buckling of shoulders, rather, the bullets were being deformed at the ogive. I tried different bushing sizes and ultimately had to pick up a few different sized mandrels as well. Once I found the right mandrel, the bullet deformation went away.
 
How did the bullets look? Were they deformed from the increased pressure on the seating stem?

When I was trying to form Peterson 270 Win brass to 6.5 Sherman, I ran into neck thickness issues as well. However, I didn't have buckling of shoulders, rather, the bullets were being deformed at the ogive. I tried different bushing sizes and ultimately had to pick up a few different sized mandrels as well. Once I found the right mandrel, the bullet deformation went away.
The bullets were not deformed and measured the same diameter as unloaded bullets. And yes, I will need to try different bushings and expanders to find the combo that works.
 

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