Stainless Media Tumbling

[ASbobcat]

This method is great for making brass look like new, but I no longer use it for brass I use in serious accuracy shooting, especially in tight neck chambers.

The issue is with work hardening of the case mouth. All tumbling will "peen" the case mouth to some degree but the stainless media enhances the effect.

I ruined some brass by not checking loaded case neck O.D. Because of the spring back after re-sizing in a bushing die I was experiencing flaring of the case mouths. This flaring resulted in loaded necks .002-.003 larger than normal which in some cases was equal to or greater than my chamber dimension. With no room for the neck to release the bullet I was experiencing dangerously high pressures. In some instances this resulted in blown out extractors and ruined primer pockets.

I have spoken with the manufacturers of these tumblers and they are aware of the problem. I now use carbon remover (Bore Tech C4, or similar) to clean the outside of the case, a PP uniformer tool to clean the primer pocket and brush the neck inside with graphite.

I anneal every fourth firing before re-sizing.

 

[Dusty Stevens]

All i gotta do to mine is give it a quick twist inside n out with a chamfering tool and im back in business. If all i wanted to do was remove outside neck carbon id give it a quick twist in 4o steel wool or krazy kloth and run a wore out bronze brush into the neck once. Been doing that on ppc for 20yrs successfully

 

[ASbobcat]

All i gotta do to mine is give it a quick twist inside n out with a chamfering tool and im back in business. If all i wanted to do was remove outside neck carbon id give it a quick twist in 4o steel wool or krazy kloth and run a wore out bronze brush into the neck once. Been doing that on ppc for 20yrs successfully

Glad someone else realizes brass doesn't have to be pretty inside to shoot good.

 

[jlow]

Peening associated with SS-cleaning is something that is well known in the reloading community and solutions are also well known.

Basically peening is due to case mouth colliding with other cases. To avoid this:

1. Reduce the number of cases you are tumbling i.e. no more than 50 rifle cases per run.
   
   
2. Reduce the time you tumble. The idea is not to get shinny pretty cases but to clean the case and the primer pocket - never more than 1 hour.
   
   
3. Increase the amount of media from 5 lb to 10 lb since the media acts as cushion to collision and this also allow faster cleaning.
   
   
4. Do not over anneal your necks – over anneal necks are softer and the peen easier.

If you follow the above 4 rules, you will not have any problem with peening.

 

[CH Luke]

Peening associated with SS-cleaning is something that is well known in the reloading community and solutions are also well known.

Basically peening is due to case mouth colliding with other cases. To avoid this:

1. Reduce the number of cases you are tumbling i.e. no more than 50 rifle cases per run.
   
   
2. Reduce the time you tumble. The idea is not to get shinny pretty cases but to clean the case and the primer pocket - never more than 1 hour.
   
   
3. Increase the amount of media from 5 lb to 10 lb since the media acts as cushion to collision and this also allow faster cleaning.
   
   
4. Do not over anneal your necks – over anneal necks are softer and the peen easier.

If you follow the above 4 rules, you will not have any problem with peening.

+1 on 1-3. Great advice.
Wouldn't annealing after cleaning take care of most of the potential harm in #4?

 

[jlow]

+1 on 1-3. Great advice.
Wouldn't annealing after cleaning take care of most of the potential harm in #4?

The key is not “annealing” but “over annealing”

 

[waldo1979]

I've been experimenting with my SD tumbler and I agree. SA yields poor accuracy compared to alternatives. My latest attempt was 50 brass, #7 media, 1 tbsp dish soap and 45 minutes. Leaves some carbon in the necks and minimal peel. I'll let you know how this works out.

 

[Endyo]

A quick pass in my Giraud after tumbling makes quick work of the peening.

As an alternative a quick hand chamfer also helps significantly.

I have drastically reduced the time I wet tumble, but inevitably it still occurs.

You have to weigh the pros and cons of wet tumbling.

Peening and squeaky clean brass (increased bullet grip).
Possible increased work hardening from being tumbled in steel, haven't seen it myself but there may be some effect measurable or not.
I also haven't noticed a real effect of brass being too clean, but others with different accuracy requirements may have.

 

[jlow]

A quick pass in my Giraud after tumbling makes quick work of the peening.

As an alternative a quick hand chamfer also helps significantly.

I have drastically reduced the time I wet tumble, but inevitably it still occurs.

You have to weigh the pros and cons of wet tumbling.

Peening and squeaky clean brass (increased bullet grip).
Possible increased work hardening from being tumbled in steel, haven't seen it myself but there may be some effect measurable or not.
I also haven't noticed a real effect of brass being too clean, but others with different accuracy requirements may have.

Don’t rely on chamfering/deburring to remove the peening as it can get pretty significant. A good way to check is to run your finger nail from the shoulders towards the mouth of the neck. If it catches, then peening still exists – I know this from personal experience.

There should be no peening if the 4 steps I outlined above is followed. Trying to “fix” it afterwards is not the best way.

 

[Endyo]

I'll definitely play around with it more. I usually tumble with 8-12lbs of media, but admittedly I do about 100 pieces of brass at a time.

My current combinations still have peening.

I did run a small batch a few nights ago. Less than 50 rounds probably about 7-8lbs of brass.

When I get home I'll take some pics and report on the case mouths.

Don’t rely on chamfering/deburring to remove the peening as it can get pretty significant. A good way to check is to run your finger nail from the shoulders towards the mouth of the neck. If it catches, then peening still exists – I know this from personal experience.

There should be no peening if the 4 steps I outlined above is followed. Trying to “fix” it afterwards is not the best way.

 

[Endyo]

50 cases, deprimed. 8lbs SS media. 2.5 Hours.

Tumbled longer than usual on this batch. I'll try it again to your specs jlow and maybe post results.

Peening is present but hard to see on picture. It's more that the case mouths peen inwards and require a chamfer than needing an outside deburring.

 

[jlow]

Time is a huge factor, try the 1 hour and see how it works for you.

 

[Endyo]

Time is a huge factor, try the 1 hour and see how it works for you.

10-4.

I've found with 1 hour the brass is shiny. There will be some residue in the primer pocket, but a lot cleaner than several hours using traditional dry media.

I have a batch of 40 cases going with 10lbs SS media. I'll pull it here in about 40 minutes and post pics! Interested to see the results myself.

 

[Just Dave]

The biggest problem I see with the pins is just about everybody recommending people dump cases in, and let em spin for HOURS..
Completely not necessary,, I agree with the addition of more media, I use 10# in my little Extreme17, never more than 50 rifles cases at a time.
I deprime, then dump them into luke warm water, with ONLY a little dawn,, Spin for 20 minutes,, and RINSE the dirty water..
Refill, add some more dawn, and another 20 minutes tumbling,, you'll notice the water is dirty again, but not as bad as first time.
This is when I rinse media and brass out well, add a little soap and some lemishine, and another 20 minutes turns all brass shiny..
Ok, maybe they don't glow like a pile of gold bricks, but they are clean of old residue and not over-tumbled.
.
I have never seen peened over case necks like that, I would be alarmed too if that came out of my tumbler

 

[Endyo]

Lot better with less time. Still notice that the case mouth has some peening.

1-hour, 10lbs

Pockets are 80-90% clean


May try a 13 lbs Media and a half hour next time.

 

[Dusty Stevens]

I cant help but notice you have a heavy chamfer on your case mouths- i call it a cookie cutter. I think if you chamfered less you wouldnt have the peening issue. I can tumble mine for 2hrs in 5lbs of pins with 100cases and dont see that. One very quick touch with the chamfer tool and they look exactly like they did before i tumble em. I have done 50,100,200 ppc cases with the extremely fragile .262 necks and never seen that

 

[hotshot828]

I cant help but notice you have a heavy chamfer on your case mouths- i call it a cookie cutter. I think if you chamfered less you wouldnt have the peening issue. I can tumble mine for 2hrs in 5lbs of pins with 100cases and dont see that. One very quick touch with the chamfer tool and they look exactly like they did before i tumble em. I have done 50,100,200 ppc cases with the extremely fragile .262 necks and never seen that

I cant help but notice you have a heavy chamfer on your case mouths- i call it a cookie cutter. I think if you chamfered less you wouldnt have the peening issue. I can tumble mine for 2hrs in 5lbs of pins with 100cases and dont see that. One very quick touch with the chamfer tool and they look exactly like they did before i tumble em. I have done 50,100,200 ppc cases with the extremely fragile .262 necks and never seen that

I also have no problem with my brass either. Use 5 lbs. of pins,100 pieces of brass and fill the tumbler to the top with water. Tumble for 2 hrs.

 

[jlow]

Lot better with less time. Still notice that the case mouth has some peening.

1-hour, 10lbs

Pockets are 80-90% clean

May try a 13 lbs Media and a half hour next time.

Sorry but impossible to see with those photos. Just want to do a sanity check on the term “peening”. “Peening” is the peeling back of the end of the neck so that if you slide your nail from the shoulders to the case mouth, the nail will catch on the lip that is peen back. “Peening” is not the small impact pattern on the end of the case mouth. Not saying that is what you are saying but just want to make sure we are all on the same page.

 

[Endyo]

Sorry but impossible to see with those photos. Just want to do a sanity check on the term “peening”. “Peening” is the peeling back of the end of the neck so that if you slide your nail from the shoulders to the case mouth, the nail will catch on the lip that is peen back. “Peening” is not the small impact pattern on the end of the case mouth. Not saying that is what you are saying but just want to make sure we are all on the same page.

No. I must be using the term wrong. I don't experience that condition.

What I'm describing is the brass rolling inside towards the case mouth.

If you take a sharp instrument like a dentist pick and drag it across the inside of the case mouth it will likely catch a small amount. This goes away after chamfering.

 

[Endyo]

I cant help but notice you have a heavy chamfer on your case mouths- i call it a cookie cutter. I think if you chamfered less you wouldnt have the peening issue. I can tumble mine for 2hrs in 5lbs of pins with 100cases and dont see that. One very quick touch with the chamfer tool and they look exactly like they did before i tumble em. I have done 50,100,200 ppc cases with the extremely fragile .262 necks and never seen that

Thanks for the feedback Dusty.

I didn't neck turn until recently and most my dies were factory.

Due to the high neck tension if I didn't use an aggressive deburr/chamfer during seating the case mouth would scuff my bullet jackets.

My aggressive chamfer is a throwback to those days. I'll be backing it off since my handloading techniques have evolved.