Deformed shoulders in brass

distorted shoulder brass

  • PMC 223 brass neck buckling issiues

    Votes: 2 66.7%

  • All other military .223 brass loads just fine

    Votes: 1 33.3%
  • Total voters
    3
  • Poll closed .
T

tecuhma

Inactive
I am currently using an RCBS Supreme Rock Chucker press for reloading my rifle ammunition.
In using this press with .556 military brass after full length resizing, primer pocket cleaning-deburring and ultra sonic cleaning, I then trim the range brass back to correct size. (1.750).
Now I reload with 3031 (22 grs) and here is were I encounter a problem. As I was seating my bullet Horandy 55gr -ax to a LOA of 2.130 my the shoulder on some brass notably P.M.C. buckled rendering them useless.
might add that after ultra sonic cleaning Ii dried my my brass in a dedicated oven for 15 min.@ 150 degrees.
All other brands of brass work well with no issues.
When I got out in 1970 there was plenty of PMC bras made in Korea priced for cheep.It shot well and was respected.
Back to my story, I even backed out the bullet seating die 1/2 turn so that the press would not roll over. It helped but I'm still not ha
ppy with this.
I had the same problem with a Lyman All American Press
set up in .308 years ago. (Different dies)
Can any one offer some advice.( Do you think that flame hardening may help?)
 
Check neck wall thickness.

My guess is that it's thick enough to bind against the die and bullet during seating, coming out with the same end-result as seating-while-crimping.






(For the record, I hate PMC brass. ...But my brother thinks it's just fine. "Take it..." ;))
 
As I was seating my bullet Horandy 55gr -ax to a LOA of 2.130 my the shoulder on some brass notably P.M.C. buckled rendering them useless.
Click to expand...

I would suggest you get familiar with your press, I have no fewer than 15 presses, not one of them 'roll over'. I do have presses that cam over, I have presses that cam over and I have presses that do not cam over. I also have directions for presses. I have directions for presses that cam over and I have directions for presses that do not cam over and I have one sheet of directions that cover both presses, the dam over and the non-cam over.

Die adjustment: I would suggest you raise the ram with the case in the shell holder, then! adjust the die down to the case. Once the die contacts the shell: STOP:eek:, then back the die off and secure the die to the press with the lock ring.
If you are crimping trim all the cases to the same length. Then, decide if your press is a cam over press or a non-cam over press.

F. Guffey
 
The seating die does not have case body support. When seating bullets the alignment between the case neck and bullet is critical. There is about 2,000 miles of space used-up on reloading forms discussing and cussing neck tension, interference fit or bullet hold. I can measure bullet hold in pounds, I can measure interference fit, the one thing I can not do is measure neck tension. I Have tension gages, all of my tension gages are calibrated in pounds, I do not have a conversion from tensions to pounds.

The first tension gage I used was calibrated in thousands of pounds.

F. Guffey
 
If I am following you correctly, it sounds typically like applying excessive crimping force during bullet seating that causes the case to buckle below the shoulder. This is a somewhat common occurrence and easily corrected by backing off some on the seating die to relieve the crimping pressure. Nothing to blame the press for due to cam-over. Pull the bullets and resize the cases to restore them to normal. The case wall is not supported by the inside of the seating die that allows the buckling to happen when too much crimping pressure is applied.
 
Probably a reloading problem. You made reference to PMC brass from the 70's. I remember that scrap. It came in a plain brown or white box and was the thinnest brass I had encountered. I used some new box ammo in my AR and it tore the head off most of the rounds when it extracted. I am sure it has vastly improved by now, but you did not mention how old the brass was.
 
IMHO, PA-Joe has the answer. When you trimmed your brass, you left the case mouth flat and that, combined with the bullets you are using, results in the bullet catching on the case mouth and buckling the case neck/shoulder. Chamfering the case neck is the obvious solution; boat tail bullets would be another.

Jim
 
I think this problem is related to a seating die interference issue(trying to crimp into a bullet with no cannelure or similar). I load prepped .223 cases on a "semi-progressive" turret press using a full length sizing die set to neck size as part of a powder check station. There's no expander involved but I still don't "collapse" shoulders even with flat base bullets.
The ONLY instances I've seen with shoulders bulging or "collapsing" have been caused by the seating/crimping die.
 
Other posters above have it right.

I ran into the same problem with 223 (and 30-06 now that I think about it). At first, I thought it was because I wasn't chamfering the neck, but the cases were still buckling even after chamfering.

In reality, it was caused by the crimping shoulder in the seating die. I backed off the seating die body, then screwed in the seating stem until I had a good OAL again. Voila, problem solved. Even a tiny amount of excess crimp will cause a case to buckle.

Most of the 223 cases I currently load are PMC, and I haven't had a single one buckle since I stopped crimping.
 
This is caused by friction where the bullet enters the case. Check neck thickness, but also look at deburring the inside of the case neck properly. Other problem could be that the case has hardened and needs annealing. When the expander ball expands the case neck after sizing the tension on the hardened cases is much more and therefore these necks would be tighter than others - thereby causing it to collapse.
 
Part of the problem here is that the OP has not adequately described the actual condition of the deformed case. Some of us are assuming that the condition is a bulging of the case below the shoulder, typically caused by over crimping; while others are assuming a collapsed case neck that can happen when seating an over-sized lead (or even a flat base jacketed) bullet into a case that has not been flared. Until we know the condition of the deformed case, either side of this debate could be correct. Using the correct terminology to describe the situation should put the issue to rest. His use of the term "buckled" would tend to favor the over crimping possibility resulting in bulging but that does not render the case useless since the case can be resized and ironed out. But a collapsed neck would make it useless. Get back to us OP with a better description of the situation.
 
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Part of the problem here is that the OP has not adequately described the actual condition of the deformed case. Some of us are assuming that the condition is a bulging of the case below the shoulder, typically caused by over crimping; while others are assuming a collapsed case neck that can happen when seating an over-sized lead (or even a flat base jacketed) bullet into a case that has not been flared. Until we know the condition of the deformed case, either side of this debate could be correct. Using the correct terminology to describe the situation should put the issue to rest. His use of the term "buckled" would tend to favor the over crimping possibility resulting in bulging but that does not render the case useless since the case can be resized and ironed out. But a collapsed neck would make it useless. Get back to us OP with a better description of the situation.
Click to expand...

Dents are dents, dimples are dimples and bulges are bulges, I believe that is the way Truthful James would describe the problem, or was that Oliver?

F. Guffey
 
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