Stainless Pin Tumbling "too clean"?

[Huntz]

Not to get off the subject,but several folks mentioned cold welding.I have been reloading since 1965 and have never had that happen.I used to shoot CMP with a AR15 in Service Rifle.My friend had a Dillon 650 and we loaded 5 gallon buckets full of ammo and never experienced cold welding.So how does this supposedly happen?

 

[Bruce Treloar]

I neck turned my light bench gun case necks in 22PPC so they did not need sizing after firing. The idea was not to misaline the necks by pulling over a neck sizing button and prevent neck hardening due to over work. I cleaned the inside case necks with a nylon brush and the outside with a shredded cotton non abrasive fabric thinking the cases should last for many firings. With each firing the neck tension decreased and after 6 firings it was necessary to very slightly size the outside of the necks to hold a bullet with hunting type tension. I concluded the wear on the case necks was from firing only so any tumbling or abrasive cleaning is not an option for me even in hunting cases.

 

[Eagleye242]

I have personally experienced "Cold welding" of the bullet to the neck of a case.
Squeaky-clean brass, Jacketed bullet, and sitting for about 9 months as loaded.

The cartridge was 38-55 Winchester. The first 2 rounds fired showed no indications up
of any problem, but the 3rd shot was well out of the group, and when I extracted
the case, a good portion of the neck was missing, leaving a short, ragged-edged
case. I checked the bore. all seemed good, so I fired several more. At about #8, I got
another of the "missing neck" incidents.

Having enough of this nonsense, I packed up and went home. Took the remaining
12 rounds, and started breaking them down. Three of the remaining loaded rounds
were so welded, that I could not pull them with a collet puller.

I put these in my press [Bonanza CO-AX] and tried seating them a bit deeper so I could
pull them. One of the 3 broke free, the other two folded the cases just below the bullet base.
I had to peel the brass off the bullet with sidecutters and the metallurgical bond was
clearly evident, transferring copper to the brass case, and brass to copper as well.

I concluded that this phenomenon requires 3 factors to occur:
1. The case and bullet must be very clean.
2. The metals must be dissimilar or compatible alloys.
3. Some time must pass for the welding to take place.

No more super-clean cases for me!! I have ammo around that is 2 or 3 years old. I do
not want to experience this again. I now tumble dry exclusively, using walnut or treated
corncob. I can forego the shiny, shiny brass in favor of consistency and safety. Fortunately,
no apparent damage to my Reproduction M94 rifle. Dave.

 

[25WSM]

Cold welding is a fact. But it takes time to happen. You probably shot through your buckets of ammo before it had a chance. The 2 dissimilar metals being together cause this reaction. And moisture of any kind makes it worse. Take any old ammo you have laying around and try and seat the bullets deeper. You will feel them break free before they slide easily. Sometimes you can hear a crack sound when they let loose.
Shep

 

[atblis]

this got me thinking, once the carbon starts to build up when is there too much? I guess every powder would be different, the conditions at the shot, I see a rabbit hole.

I kinda suspect carbon buildup inside the neck is in some ways self limiting. Anyways, I give each case a couple strokes with a nylon neck brush like others have mentioned.

 

[crystalgayleguy]

I once chased the shiny brass craze but have all but switched back to dry tumbling after sending several batches of brass through my Frankford wet tumbler with SS pins. Man do they look good coming out of the wash and I never really had a problem with getting the cases dried (used a food dehydrator) and media separated, but it's a much more involved process than dry tumbling ... both in everything you need to get the job done as well as your time.

My biggest gripe however was how many stuck cases I got after the wet wash. I had to be way more diligent with my lube in order to not stick that squeaky clean brass in the sizing die. I don't know if you'd call it cold welding, but I also had some weird issues with brass being deposited inside the sizing die (probably from poor lube application) which made some bad markings on brass that I was running through it, I ended up having to polish out the inside of that die real good.

I loved the shiny brass but a quick hour in the dry tumbler is so much quicker and easier and ultimately gets the job done just fine.

after wet tumbling put in vibrating tumbler to dry tumble

 

[mrmax]

I'm one of the first to use SS pins on cases. That goes back to the Mid 1980's. In the years that followed I won 5 US national rifle event set numerous national records and have one if not the most number of wins in NZ . Here are the facts . I use a Lortone 1.5 gallon rock tumbler their on the web and there is a rock shop that sell these here in NZ , these will last a life time . The SS media I use is the stuff I made 30 years ago .8 x 3 mm approx. The big issue is that the case need to be sized and de-primed first and the lube needs to be a water soluble and the only one that works for me is RCBS Lube 2 and I use a pad that RCBS sells , fantastic product. I tumble for 8 hours as that worked out when I left for work till I returned . In the US I used Ivory liquid dish washing . No NZ product does as good , after a lot of experimenting I settled on some ECOLAB concentrated Detergent , Solitaire these come in 5 pound jugs and las for years , I have several I can sell , let me know if you need some. The issue is most NZ Detergents do not have enough surfactants to keep the contaminants from re-sticking to the brass . One other thing that helps is have the deep fry basket and the tub you use ready as soon as you turn the tumbler off or the dirt will start to stick on the brass again ! If you need some of this fantastic detergent contact MR.MAX Ltd .

 

[BountyHunter]

Thank you for the info! So far it looks like I will be switching to stainless pin tumbling.
Any more info anyone?
Thanks, Larry

I will sell you my setup then.

 

[JustMe2]

I have one rifle that will shoot factory at absolutely incredible accuracy.
Neither the previous owner nor myself have been able to match it.

Unfortunately it really hurts because the factory ammo is very expensive.

Yes, I can believe you found an accurate factory round for your one rifle. However, one example of an accurate factory load compared to a thousand examples where handloads are more accurate than factory loads does not contradict my previous comment about carbon in the necks possibly helping accuracy.

 

[littlebighorn]

Wow,
So does anyone want the brand new SS tumbler I just bought?

 

[mrmax]

Wow,
So does anyone want the brand new SS tumbler I just bought?

What is the problem I can get you through it , just ask .

 

[Oldtime Shooter13]

This thread confirmed what I thought may be happening. I just could not make myself believe that cleaning my would cause any issues. I have change my thought now reading the posts.

On a recent trip to the range I noticed erratic SD/ES readings from my 6.5 Creedmor. This was from a proven load that I have shot before. These were hand loads that I had recently changed my seating depth out closer to the lans. I had loaded 20 rounds to try and first three shots were same cloverleaf as previous loaded. Then I started getting erratic velocities. My group opened up and was now throwing shots and I started noticing flattening primers. I stopped shooting still have 10 rounds. I thought that seating the bullets closer to the lans might be my issue causing higher pressure. I had loaded thes bullets about 2 months prior to this range trip. When I started seating these loads to my pervious seating depth, I noticed some of the loads would snap. Ah ha, neck weld? Out of the 10 rounds that I seated I had I had 6 that had neck weld? Never have I had this before, I so I started going through what I have change in my reloading process?

I started cleaning my brass with wet stainless steel pins to a nice beautiful shinny like new condition. Reading this post made me start thinking about the process for my bolt action rifles. I don't need petty brass, I need accurate reloads. I am going to let my rifle brass become dirty again. it is going to take me a little while because I like my like new shinny brass that cleaned everything I have for rifle brass over the winter. The next time I go shooting I am going to load before I go and see how my loads shoot. I curious if my cleaning process is the cause?

I will continue to clean my auto pistol brass that I really don't care as long as I can hit a 18" target at 25 yards. I'm not trying to shoot tiny groups.

 

[mrmax]

I shot ammo that had been loaded and stored for a year in a warm and dry environment that I would not normally have kept for a registered match. I ended using when I came back to the US for a competition in an approved match @ 500 yards at Camp Atterbury. That is the ammo that I shot a 200-20 X Iron sight and prone setting that range record , had it been a registered match it would have been a US National record . That brass was SS tumbled before loading over 6-12 months before shooting . And yes those had been fired cases , never annealed ,,,.

 

[jbs2014]

I have used ss pins for a long time and cleaned over 100,000 cases. I have a large tumbler, 20 gallons. I use 25 pounds of pins and Hornady sonic clean as the cleaner. It only takes two tablespoons. All of my cases look great except 50 BMG. They were beat to death. Figured out it was the cases full of pins falling on the other cases that beat them up. First, they are heavy but fill with pins they get really heavy. I have not had other cases up to 338 Lupua come out looking beat up. Tried putting fewer 50 cases in the tumbler but they still get beat pretty bad. As an experiment, try to clean one or two cases in your tumbler and see if it comes out peened. I don't think it will.

I had that same problem with .50 BMG and SS media. I have to use the ultrasonic cleaner for 50 BMG now.