Stainless Steel media affecting neck tension

jimmyjazz

jimmyjazz

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So i recently purchased a Thumblers tumbler and started using SS media.

In order I size and deprime brass, prime, load powder then seat the bullet.
I have since noticed after using SS media when I seat the bullet there is more tension on the necks and I am shaving the bullets.

I really don't want to have to resize again after cleaning and like the way the brass comes clean especially the primer pockets.
I have never experienced this with vibratory cleaner and walnut shell.

Just curious if I am tumbling too long or doing something else wrong.
Anyone else notice this?

Cheers,
JJ
 
Most folks advocate the deprime (with a universal deprimer), tumble, and then size method. Keeps your dies from possibly getting scratched up from range grit, etc, as well.

Since SS Tumbling has been shown to ding up the case mouth a bit (peening), if you are not cleaning that up before loading, I could see it shaving the bullets. Do you chamfer and deburr after sizing and before tumbling? I'd size, trim, chamfer, and deburr after tumbling and you shouldn't see any issues.
 
Though I've never had the problem with neck tension you describe, I go through the steps Valeksky outlines and have had no issues with my SS tumbler affecting brass.
 
The only reason I size and deprime before cleaning is to get the case lube off, if you're cleaning before sizing how do you deal with the case lube?
 
jimmyjazz said:
So i recently purchased a Thumblers tumbler and started using SS media.

In order I size and deprime brass, prime, load powder then seat the bullet.
I have since noticed after using SS media when I seat the bullet there is more tension on the necks and I am shaving the bullets.

I really don't want to have to resize again after cleaning and like the way the brass comes clean especially the primer pockets.
I have never experienced this with vibratory cleaner and walnut shell.

Just curious if I am tumbling too long or doing something else wrong.
Anyone else notice this?

Cheers,
JJ
Click to expand...
I chamfer the case necks after tumbling, and no issues.
 
I've been using RCBS sizing lube and have 4 bottles of it to go through but I'll pickup some of the imperial and see how it goes.

I tried chamfering the necks after cleaning and it's better but still get 4-5 out of 100 the shave hoping to get none or I'll go back to walnut in vibrator.
 
How long are you tumbling? How many cases?

I use 10 pounds of pins for about 200 308 cases in my Frankfort arsenal tumbler. I only tumble for 60-90 minutes max. Anymore makes peening worse.
 
No issues with frankford arsenal tumbler and the media that comes with it.

How do you know you have greater neck tension?

Also how would the theoretical peening of case mouths lead to shaving bullets? Peening should make them duller not sharper.

When are you trimming and chamfering in your process? Something doesnt seem right here.
 
I've been tumbling for 2 hours will try shortening the time.

I'm using 5 pounds of pins with 100 - 308 cases
I know there is more tension as I have never had a shaved bullet with walnut media only since I switched to SS pins.

I don't trim after each firing unless required, I will measure after sizing, I have tried chamfering after cleaning and its better but still get a few cases that shave the bullet.
 
I am still a walnut tumbler and noted the impressive cleaning power of the pins. As noted by others, I have read about peening of the case mouth and I read with interest this thread on increased neck tension.

If we put the two together, does this not suggest work hardening of the brass that one would get with multiple reloads is happening with the use of stainless pins as an additional work hardening source? Is it enough for a concern for case longevity and will annealing of the case mouth be required more often?

there are many variables at play, so for those with neck tension issues and stainless pins how many reloads and what brand of brass is being used here?
 
Case peening can cause excessive neck tension if tumbled too long, especially if the case is chamfered too much. For smokeless powder loads, 30 minutes in a SS tumbler is plenty long enough.
 
ryan said:
Case peening can cause excessive neck tension if tumbled too long, especially if the case is chamfered too much. For smokeless powder loads, 30 minutes in a SS tumbler is plenty long enough.
Click to expand...

Do you have proof of this.

I full size and neck size with a type s Redding die. I tumble my brass before and and after resizing. My case necks are all measured and noted within a half tho wall thickness. Once I've loaded rounds I check them with a mic and do not see any more tension then what I want within a thou also.
 
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