Case mouth flaring after annealing

[Colnagotex]

After firing and annealing 3 times my cases are starting to flare at the mouth about .003". Anyone else experienced this?

 

[geraldgee]

Pictures?

 

[Colnagotex]

 

[Colnagotex]

It's hard to see in the pics but the first one you can see light on each side of the case below the flare and the 2nd is after I ran it back through through my neck turner

 

[ngb1787]

I have seen mouths flare when chamfering and deburring are not done correctly, basically from putting too much pressure on case while performing. Are you running a mandrel thru after washing? Is the mouth hitting the die?

 

[BP1]

Time to get a Giraud buddy.

 

[Dusty Stevens]

Annealed 3 times? Are they deformed from the heat?

 

[geraldgee]

An empirical approach will help determine exactly what is causing your case mouths to flare. After each step of case prep and before moving to the next step, measure your case mouths. In short order you’ll determine which part of your case prep process needs attention. Start with a single case and go through your process until you measure a flare mouth. Do another to ensure your testing is accurate.

Good luck.

 

[Colnagotex]

I have seen mouths flare when chamfering and deburring are not done correctly, basically from putting too much pressure on case while performing. Are you running a mandrel thru after washing? Is the mouth hitting the die?

No and no

 

[Colnagotex]

An empirical approach will help determine exactly what is causing your case mouths to flare. After each step of case prep and before moving to the next step, measure your case mouths. In short order you’ll determine which part of your case prep process needs attention. Start with a single case and go through your process until you measure a flare mouth. Do another to ensure your testing is accurate.

Good luck.

I started that on a test batch today. Annealed 1 time and no problem.

 

[Dusty Stevens]

I started that on a test batch today. Annealed 1 time and no problem.

Keep doing that. Youll destroy your brass if you keep on annealing it for no reason

 

[BP1]

Keep doing that. Youll destroy your brass if you keep on annealing it for no reason

Think he means it’s the first time he’s anealed this batch.

 

[Dusty Stevens]

Think he means it’s the first time he’s anealed this batch.

Ok then. I gathered that he fired them THEN annealed 3 times and got the flare. Then he fired them and annealed once and didnt get the flare. Interesting either way. I believe with the way that neck cut looks id skim turn the whole neck it had an hourglass shape and the thicker neck at the top may explain the flaring. Its always good to turn them til they clean up 95% at least that way its as uniform as possible

 

[Texas10]

I looks like the tendency to spring back after shooting is less at the case mouth, maybe due to over softening during annealing? What annealing method do you use? If torch method, the case mouth may be getting much hotter than the neck/shoulder as heat tends to concentrate there.

 

[ASbobcat]

After firing and annealing 3 times my cases are starting to flare at the mouth about .003". Anyone else experienced this?

Do you tumble after every firing? I used to experience this phenomenon until I figured out it was due to spring back from the hardened case mouths. When you tumble (doesn't matter what media because it's the heavy case heads banging into the mouths and shot peening (work hardening) them). The longer you tumble the worse the problem becomes. Annealing does not change the differential harness between the mouth and the rest of the neck.
There is another problem that happens from this same process. The mouths can be "rolled over" creating a sharp lip on the inside. This lip can only be removed by re chamfering. You can feel for it with a dental pick.
Once I stopped tumbling I never encountered either of these issues again. Now I just brush the inside of the necks thoroughly and softly burnish the residue from the outside with 0000 steel wool.

 

[Dusty Stevens]

Do you tumble after every firing? I used to experience this phenomenon until I figured out it was due to spring back from the hardened case mouths. When you tumble (doesn't matter what media because it's the heavy case heads banging into the mouths and shot peening (work hardening) them). The longer you tumble the worse the problem becomes. Annealing does not change the differential harness between the mouth and the rest of the neck.
There is another problem that happens from this same process. The mouths can be "rolled over" creating a sharp lip on the inside. This lip can only be removed by re chamfering. You can feel for it with a dental pick.
Once I stopped tumbling I never encountered either of these issues again. Now I just brush the inside of the necks thoroughly and softly burnish the residue from the outside with 0000 steel wool.

I think we’ve proven with actual rockwell data that case mouths getting peened and beaten do not harden them. You do have rolled edges that need to be touched up with a chamfering tool but thats no big deal

 

[ASbobcat]

I think we’ve proven with actual rockwell data that case mouths getting peened and beaten do not harden them. You do have rolled edges that need to be touched up with a chamfering tool but thats no big deal

I'm not sure who "we" is, but if you're referring to the "supposedly scientific" testing, it did NOT test the case mouths, only portions of the neck BELOW the mouth. In any case, you're certainly entitled to believe what you want, and tumble as long as you wish.

 

[Webster]

I looks like the tendency to spring back after shooting is less at the case mouth, maybe due to over softening during annealing? What annealing method do you use? If torch method, the case mouth may be getting much hotter than the neck/shoulder as heat tends to concentrate there.

I anneal with a torch. When annealing in a dark room it's common to see the first 10-20 thou of the end of the neck turn red 2-3 seconds before the rest of the neck. Depends how you apply the flame The very end of the neck becomes very soft 90% of the neck is OK.

Don't know if an induction annealer has the same effect. No metal at the end of neck to pull heat away.

 

[Colnagotex]

I looks like the tendency to spring back after shooting is less at the case mouth, maybe due to over softening during annealing? What annealing method do you use? If torch method, the case mouth may be getting much hotter than the neck/shoulder as heat tends to concentrate there.

I use the AMP machine.

 

[Colnagotex]

Do you tumble after every firing? I used to experience this phenomenon until I figured out it was due to spring back from the hardened case mouths. When you tumble (doesn't matter what media because it's the heavy case heads banging into the mouths and shot peening (work hardening) them). The longer you tumble the worse the problem becomes. Annealing does not change the differential harness between the mouth and the rest of the neck.
There is another problem that happens from this same process. The mouths can be "rolled over" creating a sharp lip on the inside. This lip can only be removed by re chamfering. You can feel for it with a dental pick.
Once I stopped tumbling I never encountered either of these issues again. Now I just brush the inside of the necks thoroughly and softly burnish the residue from the outside with 0000 steel wool.

I tumble every time and never had a problem until I started annealing.