Run-out help needed

[MontanaRifleman]

Took some pics but having trouble downloading. Will try to get it worked out tomorrow, maybe use my phone camera.

The bullets are seated down below the shoulder/neck junction so that would prevent visible shrinkage. Used my percussion bullet puller to pull one of them and it didn't require anymore effort than recently seated bullets with neck tensions about .002 give or take. Also, no sign of oxidation on bullet or inside the case neck.

This also happened with 160 Nosler Partitions loaded about the same time. However, all (50) of them had a wrinkled (bulged) neck and almost none have wrinkled shoulders. The Balistic Tips were loaded into Fed Brass and the NP's into Rem.

At that time, my habit was to clean the inside of the necks with a bronze brush which I do now with a nylon brush.

 

[Bullet bumper]

Took some pics but having trouble downloading. Will try to get it worked out tomorrow, maybe use my phone camera.

The bullets are seated down below the shoulder/neck junction so that would prevent visible shrinkage. Used my percussion bullet puller to pull one of them and it didn't require anymore effort than recently seated bullets with neck tensions about .002 give or take. Also, no sign of oxidation on bullet or inside the case neck.

This also happened with 160 Nosler Partitions loaded about the same time. However, all (50) of them had a wrinkled (bulged) neck and almost none have wrinkled shoulders. The Balistic Tips were loaded into Fed Brass and the NP's into Rem.

At that time, my habit was to clean the inside of the necks with a bronze brush which I do now with a nylon brush.

Ok from teh sound of it you have not experienced bad age hardening that's good. I said it was unpredictable .
As far as bulged necks go then the problem may be incorrect adjustment of the bullet seating die . If you have the die body down too far when you push the bullet into the case the end of the neck can hit up against the end of the die .
A little bit might just crimp the bullet but a lot will push the neck back and damage it.
If you back the seater stem out and die off then run an empty case of correct lenght into the die . Run the body of the die down until it stops on the case then back off one 1/2 turn that will give you about .0357 clearance . Lock the die body then go about adjusting the seater stem to give correct seating depth.

 

[Bullet bumper]

That is some wild stuff. Interesting photos. I can see the wasp waste.

Yes it is fairly dramatic . I did use old fired cases that were fired about 20 times and were quite hard . Some had clean necks , some the bullets were just seated in dirty necks , some were moly coated seated into clean necks.
It does show that it can happen but I think that new ammo in annealed case necks would last longer and be less effected .
This ammo was stored in a 50 cal ammo box for 10 years and hardly ever opened and subjected to hot weather in summer . Infact for some years I forgot I did it . Until one day 10 years later I remembered and opened it up .

 

[MontanaRifleman]

Ok from teh sound of it you have not experienced bad age hardening that's good. I said it was unpredictable .
As far as bulged necks go then the problem may be incorrect adjustment of the bullet seating die . If you have the die body down too far when you push the bullet into the case the end of the neck can hit up against the end of the die .
A little bit might just crimp the bullet but a lot will push the neck back and damage it.
If you back the seater stem out and die off then run an empty case of correct lenght into the die . Run the body of the die down until it stops on the case then back off one 1/2 turn that will give you about .0357 clearance . Lock the die body then go about adjusting the seater stem to give correct seating depth.

I was just thinking the same thing, but peering down into the seating, the body wall is machined to the shape of the case including shoulder and neck. There is no way for the neck to be pushed down by the die.

 

[Bullet bumper]

Are you sure because some standard dies are set up to crimp in addition to seat the bullet . You just adjust it down more until it starts crimping then set your seater stem.
I can't think what else could wrinkle a case neck during bullet seating .
Anyway set the die as I said with some back off clearance and see if it still happens.
Only other thing is if the bullet jacket metal is getting shaved by a bad chamfer and that could be cutting in enough to grab and wrinkle the necks.

 

[MontanaRifleman]

I stand corrected. I was able to collapse the shoulder without fully seating the bullet.

 

[Bullet bumper]

That is a relief , you now know what to do to fix it . A lot of things come back to die adustment problems. Those pesky dies.