SS pins

[Lance21]

I've noticed after I tumble my brass in ss pins they come out with a burr around the case mouth. My question is has anybody used the ss chips and had this problem? It's getting pretty annoying having to turn the burr off every time I've cleaned them.

 

[1kbrxDave]

more pins ---or less brass is the answer to the problem.
it solved it for me.

 

[MikeMcCasland]

Yes. It's known as case mouth peening. Common issue if you leave them in the tumbler for too long, have too many cases/too few pins etc.

 

[Lance21]

more pins ---or less brass is the answer to the problem.
it solved it for me.

I've tried both. Just pulled 24 pcs out, peened fairly bad.

 

[Straightshooter1]

I've noticed after I tumble my brass in ss pins they come out with a burr around the case mouth. My question is has anybody used the ss chips and had this problem? It's getting pretty annoying having to turn the burr off every time I've cleaned them.

I always 3 way trim as my final operation, so whenever I wet tumble, it's not an issue.

The peening of the case mouths like that is not the pins but is due to the cases themselves, depending on how big and heavy they might be, beating against the mouths. That's why adding more media and/or using less brass for the amount of media you have will reduce or maybe even elevate the problem as it did for 1kbrsDave. Even a vibrator tumble can do some peening of case mouths depending how it's done.

 

[Andy3030]

I've wet tumbled tens of thousands and never had this with any of my brass. 5 pounds of pins from STM, and any amount of brass from as few as 20 pieces all the way up to 4 pounds in my Extreme Rebel 17. Never any longer than 4 hours.

 

[GLShooter]

I've wet tumbled tens of thousands and never had this with any of my brass. 5 pounds of pins from STM, and any amount of brass from as few as 20 pieces all the way up to 4 pounds in my Extreme Rebel 17. Never any longer than 4 hours.

I too have had the same experience as you have Andy. Never had a problem that I have noticed. I've done a few batches over the years..LOL I use 5 lbs of SS and whatever amount of brass I can throw in there. Usually not over 200 pieces of 223 stuff equivalent as I only use it for my load development and competition stuff the quantities are never huge. I have the big boy Dillons for that.

Greg

 

[Walt Krafft]

I threw away the pins and tumbled for an hour in Brass Juice. Best looking cases I ever had.

 

[MikeMcCasland]

To all you guys saying you don't have the issue, do this....put a nice sharp chamfer on 100 bottle neck rifle cases and dump them in the tumbler for ~2 hours. When you pull them out, inspect the chamfer. It won't be sharp anymore.

Wet tumbling peens cases; it is a certainty. If it's enough to affect your brass performance and/or if it's even noticeable via quick inspection is a different story. It might be so minor that it's easily corrected whenever you lightly chamfer the mouths, but it can also be significantly worse. I'm not saying don't use wet tumblers (I don't care either way), but it affects the case mouth.

Factors that affect/contribute to peening:

1.) Tumbling Speed
2.) Tumbling Duration
3.) Case/Water/Media ratio.
4.) Amount of brass in tumbler.
5.) Mass of brass in the tumbler.

I'm sure there are more that I can't think of, but it happens.

I can actually recall several years ago dumping ~75-100 .260 Rem cases in a Thumblers Model B w/ 5lbs of media and forgetting about it for ~6-7 hours. When I pulled the cases out of the tumbler, the case mouths had become so peened that the cases wouldn't fit over the pilot/arbor for an RCBS case trimming lathe using all the force I could muster.

I had to chamfer the hell out of the case mouths manually before they would fit on the pilot; even then they didn't move freely until I trimmed ~.010 off the case mouth.

This is obviously a "worst case" scenario, but it was certainly eye opening to me as to what was actually going on inside that drum.

 

[LVLAaron]

Like others have said... it's going to happen. If your pins/chips are new they may have sharp edges on them. Run them in the tumbler without brass for.... a long time.... and they'll soften up.

I know lots of people like to use homemade witches brew for a cleaning solution, and then tumble for 4-72 hours, which just worsens the neck conditions. I use RCBS solution or Citranox and tumble for 45 minutes, then anneal and 3 way trim. Works for me.

 

[Bill Rodolph]

I threw away the pins and tumbled for an hour in Brass Juice. Best looking cases I ever had.

What the hell is "Brass Juice"?

 

[Oso]

I know that peening happens with wet tumbling, and I hate the knee-jerk rationale of dedicated vibrating tumbler fans...."Its the Pins!!!". I'm glad to see the clarification of the common misconception that steel pins cause the peening.... nope, just case on case contact. After enough experience tumbling with your machine you know when you have a "balanced" load (right amount of brass, water, and just enough soap). When you walk into the garage/reloading room, you can tell by the sound, like some Yoga soundtrack of stones tumbling in current. There is the also "wrong" noise that sounds like metallic chalkboard... too many cases and not enough water.

I have done a lot of tumbling over the past 10 years. I have never run a load of brass for more than 1 hour. Most loads of dirty brass from AR15/AR10 Range Brass (suppressed and unsuppressed) get 45 minutes. Brass from bolt rifles and pistols get 25-30 minutes. I only tumble as long as needed for cases to come out clean (white gold), which also reduced the potential damage from peening. Yes, a finely chamfered case mouth may loose its knife-like edge, but in no way has this impacted the loading of bullets or feeding of cases.

Two panics ago (Sandy Hook) I was desperately short on brass and willing to make do with whatever I could get my hands on. If I had a bunch of extremely blackened cases (you know the ones that you don't even want to touch and can't imagine what person would/could own a weapon that could possibly every make a case that disgusting) then those foul cases would get the full 1 hour treatment, and I might even recharge with fresh water and soap after the initial 30 minutes of tumbling.

 

[RegionRat]

Rotary tumblers can peen case mouths due to the way that case mouths impact other cases (or media) with a velocity.

When compared to a vibe tumbler where the cases just vibrate over a minute distance and circulate slowly, in a rotary tumbler the cases move far enough to pick up relative speed and sometimes impact on the case mouths and stop against something hard. The main difference between the two methods is the relative impact velocity and energy.

There are many factors that affect peening, but it can and does happen when there are conditions that add speed to the impact.

 

[Ned Ludd]

I don't remember the exact source, but I also recall reading that someone did some tests a while back and suggested that a significant amount of case mouth peening was actually caused by the cases/case mouths banging into one another, rather than by the pins. That would also suggest that using too few pins, or too many case per amount of pins would exacerbate the peening issue. I typically use about 100-125 .223 Rem cases, or 100 .308 Win case per load with 5 lbs of pins in my Thumler's Tumbler. It seems to be a pretty good ratio. In any event, I don't tumble with pins more than about 30 minutes. It's more than enough to get them clean, causes little to no peening, and if there are any little bits of carbon left down in the corner of the primer pockets, it is easily removed with the uniforming tool.

 

[orkan]

I moved away from the wet process a few years ago. So very happy with my new method.

Play With Your Food: Clean Brass With Rice :: Primal Rights, Inc

Cleaning your brass is a necessity. Foreign material in or on our cases can cause all kinds of problems. Damage to expensive reloading dies, damage to rifles, and various other issues can arise if proper care is not taken.

www.primalrights.com

 

[venatic]

Don’t tumble unless you trim. Problem solved.

 

[Charlie-NY]

Something to think about:

I have a STM tumbler and use the supplied SS pins. A few years ago I tossed 2 SS muzzle brakes in the tumbler to get all the carbon/fouling off the brakes. I don't remember how long I tumbled them. When I removed the brakes they looked better and cleaner then new. But ....... when I tried to thread them back on it was a no-go. The only thing that could contact the inner threads was the pins. The threads were changed dimensionally enough to prevent them from screwing back onto the muzzles.

 

[garandman]

I always chamfer my case mouths inside and out. Never noticed peening that was seriously detrimental to my brass.

 

[Walt Krafft]

What the hell is "Brass Juice"?

Search for 'brass juice case wash' from thereloadingstation.com

 

[Hoot]

Just a thumbs up for Citranox.

Got a 4 oz sample from them and am blown away by how well and fast it works. 1 tablespoon to a full FART with softened, hot water and in 30 minutes moderately dirty cases come out clean as a whistle. I might add that I use SS chips not pins. I posted before and after images in This Thread.