I've just reloaded some .338 Federal rounds and had to cull 22 cases because the bullet was loose after seating and crimping. These have been reloaded several times and started life as .308 Norma brass. Are they just worn out and need to be junked or is there some way of using them ?
Thin Brass at Neck
- Thread starter sdlonyer
- Start date
The brass strength increases as it is worked by firing and reloading. The strength should not decrease unless you annealed them. Are you sure you have enough tension in the neck. Normally you want the neck outside diameter to increase 2-3 thou from the sized and unloaded condition to the loaded state for a hunting load. A crimp should not be necessary. What kind of sizing die are you using?
gunrunner8
CGN Ultra frequent flyer
- Location
- Kamloops, B.C.
I think that brass is done exept that you can use different sizing (posibly bushing) die. Next time use necked 358Win brass either Win or Norma brand that's what friend of mine is useing without any problems.
I wouldn't toss the brass just yet.
An old Speer reloading manual notes that neck tension, that which holds the bullet in place, depends on five things:
• diameter of the sizing die neck
• diameter of the expander ball
• case neck wall thickness
• case neck metal springback after firing and working
• bullet diameter
It says the expander ball should be 0.001" larger than the bullet diameter for jacketed bullets. That's easy enough to check out, as is confirmation of bullet diameter (unlikely but not impossible).
The thickness of the wall might be a bit harder to check unless you have a tube micrometer or something.
WRT brass strength increasing when it's worked, not really. It gets harder, less ductile, more brittle, less able to be shaped, less springy but not stronger. It's called 'work hardening' and the more times you've resized and fired, the harder your necks will get, especially if the chamber of your rifle is somewhat oversized or if you're using hot loads.
How many times have you reloaded these ones? If 'several times' means more than three or four times with hot loads, you might - might - have a work-hardening issue as Ron AKA suggests. You can either get new cases or anneal them. Have you had any split necks (they're indicative of work hardening)?
Another possibility - and I had it happen not long ago with some .45 rounds I was loading - check to ensure that you have proper set up your dies in your press.
Badly-made dies are a possibility, but I get the feeling you've used them before with good results, is that right?
An old Speer reloading manual notes that neck tension, that which holds the bullet in place, depends on five things:
• diameter of the sizing die neck
• diameter of the expander ball
• case neck wall thickness
• case neck metal springback after firing and working
• bullet diameter
It says the expander ball should be 0.001" larger than the bullet diameter for jacketed bullets. That's easy enough to check out, as is confirmation of bullet diameter (unlikely but not impossible).
The thickness of the wall might be a bit harder to check unless you have a tube micrometer or something.
WRT brass strength increasing when it's worked, not really. It gets harder, less ductile, more brittle, less able to be shaped, less springy but not stronger. It's called 'work hardening' and the more times you've resized and fired, the harder your necks will get, especially if the chamber of your rifle is somewhat oversized or if you're using hot loads.
How many times have you reloaded these ones? If 'several times' means more than three or four times with hot loads, you might - might - have a work-hardening issue as Ron AKA suggests. You can either get new cases or anneal them. Have you had any split necks (they're indicative of work hardening)?
Another possibility - and I had it happen not long ago with some .45 rounds I was loading - check to ensure that you have proper set up your dies in your press.
Badly-made dies are a possibility, but I get the feeling you've used them before with good results, is that right?
RCBS resizing Die..the bad brass after the sizing are 22 out of 100...so if it is the sizing die why not all?... I'm not sure of how many times this brass has been reloaded...bought it as once rloaded .308 but that is taken on faith.
Assuming you ran them all through at the same time, with the same settings, logic would suggest that it's either springback or case wall thickness as you originally suggested. The die, the expander ball and the bullet diameter would all be the same, so perhaps those are less likely.
If the cases are all one lot, it's hard to think that some would have thin neck walls and not the others. On the other hand, you aren't sure of their provenance...
Have you checked them all for length? Trying to think of what else might cause just some to fail.
I'd be tempted to anneal the 22 and see if that improves things. You should be able to tell right away if you run a couple through the reloading process without primer or powder.
One of those little things that makes life interesting.
If the cases are all one lot, it's hard to think that some would have thin neck walls and not the others. On the other hand, you aren't sure of their provenance...
Have you checked them all for length? Trying to think of what else might cause just some to fail.
I'd be tempted to anneal the 22 and see if that improves things. You should be able to tell right away if you run a couple through the reloading process without primer or powder.
One of those little things that makes life interesting.
You have to measure it so you can see how much of an increase you are getting when you seat the bullet. Also have you measured your expander ball? Another thing to try is sizing a case without using the expander ball, and then checking to see what the neck OD is before and after seating a bullet.
Are you full length sizing or neck sizing? Have the cases been trimmed many times? If the brass is getting thin, it must be going somewhere. Neck sizing usually causes the brass to stay shorter and not need much if any trimming.
Are you full length sizing or neck sizing? Have the cases been trimmed many times? If the brass is getting thin, it must be going somewhere. Neck sizing usually causes the brass to stay shorter and not need much if any trimming.
