Case mouth flaring after FL sizing.

imalamoud

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GunNutz
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Hello,

Calling for expert opinions: What could cause 6.5 Creedmoor case mouth flaring similar to below after FL sizing? Using Forster FL die.

52448024966_e58c249453_c.jpg
 

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Does the case look the same before seating the bullet?
It could be the friction of seating the bullet that flares the case a bit
A lee factory crimp die would prob fix the little bit of flare
maybe your brass needs annealed?
 
Thank you for the suggestions. I shall definitely chamfer during the next cycle.

But do you think it could also be related to (ideas from the internet)?:

- excessive wet tumbling with ss media.
- die's expander ball position
 
ball expander, too big or ram it into the brass too fast, roughly.
Flat based bullets may add to it. Chamfering will help that.
Most likely need to get rid of the flare before trying to chamber and shoot the round, Lee Factory Crip die is always handy yo have for funky issues
 
The brass does look somewhat battered. cou: I know a lot of gunners use steel pins, so I'll run and hide now.
 
I’ve never had that problem from wet tumbling.
But did have the same issue as your having when I didn’t champfer
However I rarely use the pins anymore, just deprime, add dawn dish liquid and lemi shine to hot water.
Turns out clean and shiny.
 
Guess chamfering would help to remove some of the flaring, would need to remove bullets and re-do the lot.

I checked the batch and virtually all cases which went through Forster FL have flaring. Thus, it cannot be wet tumbling, some would have it but not all.

Narrowed to either

- die's expander ball position or die's production defect
- insufficient annealing time in the batch

What is the sufficient annealing time indicator in your opinion - the flame turns red, certain time in the flame or else?
 
What is the sufficient annealing time indicator in your opinion - the flame turns red, certain time in the flame or else?

Annealing time depends on so many different factors, get some tempilaq to take the guesswork out of it.
Available at welding supply stores.
 
Stop just before flame color change.
Flame time should be between 4-5 seconds, I am always right at the 5 seconds with my set up. To short of time, it won’t be consistent, too long and it flames color will change and the heat will travel down the case too far.
This would be for a 270/6.5/7mm sized case.
 
@thump_rrr
1) Yes 1.91
2) Re-checked the die, tried with and without expander, same result
3) That time after sizing of the lot checked each case length, trimming was not required. But did not notice flaring and did not chamfer.
 
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