cob medium question

[crankyoldlady]

Got a new tumbler. Came with cob medium. I've never used anything but walnut.

First test batch I notice about 30% of the cases have a tiny piece of cob in the flash hole. Never had that happen before.

They are easy to remove. A light poke with a toothpick does it.

I'm thinking about just leaving them there and prime away. Surely the primer will blast right through.

Go ahead, tell me my pistol with blow up taking my arm and head with it.

 

[snakeye]

No you don't want to do that....if you have never had issues with walnut the just use that.

 

[ACORN]

I would think clogged flash holes would lead to inconsistent ignition.
Why not just poke the hole?

 

[crankyoldlady]

I would think clogged flash holes would lead to inconsistent ignition.
Why not just poke the hole?

Its not as if they are clogged solid. It'll be a little piece with some daylight. Some times a light tap on the bench does it.

I guess I'm lazy. Sorting, searching, and poking is so tedious.

 

[rockquarry]

I've found some that were tightly lodged. A primer might blow them out and might not. Easier to do it the right way. You won't get much mileage out of a toothpick. Something sharp and pointed like an ice pick or dental tool works a lot better.

 

[mike campbell]

Sounds like you're de-priming before you polish? If so, why would you run dirty cases thru your dies? The first thing I do when cases come back from the range is tumble them. If there's something in the flash hole after that, it will go out with the primer.

 

[dr. mordo]

I use cob, and don't de-prime first. Works great.

 

[arjay]

I switched to pet bedding from Pet Smart.Cleans well and no clogged holes

 

[bigggbbruce]

I guess I'm lazy. Sorting, searching, and poking is so tedious.

Toss the brass back in after you've removed the cob.. a few seconds should loosen up most of them..

 

[Collo Rosso]

I switched to pet bedding from Pet Smart.Cleans well and no clogged holes

There's a bunch of materials they use for pet bedding. I look for the reptile bedding that's crushed walnut. I also de-prime after tumbling.

 

[daniel lawecki]

First off you'll have FTF and I use a course corn media. I also tumble with old primers still in. You don't want to have poor burn and a stuck bullet in barrel.

 

[gwpercle]

Tumble the brass unsized, with the fired primers in place. Next step is to size the and deprime the clean cases. Clean cases are easier to size and the depriming will take care of any pesky hole cloggers.
After many years of trying stuff that's not made for case polishing I can tell you the treated shell media sold by Midway USA is the best value.
Pet bedding materials are usually not the correct size. The treated shell polishes and lasts a long time. Corn cobb is softer and doesn't polish like the treated nut shell.
You can get the nutshell lizard stuff but it's not treated....now you have to buy additives and the proper additives ( Rooster Labs polishing additives) is expensive...it eats up your savings...just get the stuff from Midway USA...much better deal than DIY with lizard litter.
Gary

 

[Mike SC Hunter]

Lizard litter with a cap full of Nu-Shine car polish works as good as anything. As far as a clogged flash hole. It's a non issue. The primer will blow it out. Been polishing and loading rifle cases like this for years.

 

[Nevada Ed]

No big deal.

What is an extra Squib or two?

 

[SMSgt]

Any primer that doesn't blow a piece of corn cob media out of a flash hole is a dud.

 

[crankyoldlady]

Sounds like you're de-priming before you polish? If so, why would you run dirty cases thru your dies?

I'm not sure why it sounds to you like that's what I'm doing but since you asked...

Dirty brass is washed when I get home from the range. Next, I sort by caliber and deprime on a dedicated press using a universal depriming die. Then I tumble. I like to start with clean polished brass when I am ready to resize and flare.

I'm not new to handloading.

 

[Andy Lowry]

What you describe is why I switched to walnut. Corncob seems to work faster, but I'm too lazy for that extra step of checking the pockets. It's not quite as bad as having somebody next to you at the range shooting !%$## small primer .45, but it's close.

 

[DumpStick]

I also deprime, using a universal deprime die, prior to washing and tumbling.

And, I also got tired of having to poke the cob media from the primer holes.

Which is why I switched to ground walnut shells. With a dab of Nu-Finish, and a tiny splash of mineral spirits, it does everything I need done, and doesn't clog the flash-hole.

 

[stansdds]

You definitely do not want to leave anything in the primer pocket, flash hole or inside the case!

I have always used crushed corn cob media and I learned that it is best to clean the cases first, then run them through the resizer/depriming die.

That corn cob is not going to clean fouling from the primer pockets, so if that is your goal, then I suggest manually cleaning the pockets with a primer pocket brush.

 

[SMSgt]

I also deprime, using a universal deprime die, prior to washing and tumbling.

And, I also got tired of having to poke the cob media from the primer holes.

Which is why I switched to ground walnut shells. With a dab of Nu-Finish, and a tiny splash of mineral spirits, it does everything I need done, and doesn't clog the flash-hole.

Curious here. What is the purpose of the mineral spirits? It seems as if it would counteract the polishing/lubing effect of the Nu-Finish. Like mixing solvents and lubricants.

 

[muddocktor]

Curious here. What is the purpose of the mineral spirits? It seems as if it would counteract the polishing/lubing effect of the Nu-Finish. Like mixing solvents and lubricants.

I would imagine it is to thin the wax so that it is distributed over the media better and will evaporate in short order, leaving the media thinly coated with the wax.

With that said, I've been using the Lyman Green media for 25-30 years at least as it does a nice job of cleaning and polishing the brass and lasts a long time also. It's a corn cob media and it will get in the flash holes, but I clean my cases before I resize and deprime them when I am not wet tumbling.

 

[crankyoldlady]

Maybe all I need to do is put the depriming pins (I removed them) back in my sizing dies. The pin would knock out any thing in the primer pocket.

 

[mike campbell]

Tumble the brass unsized, with the fired primers in place. Next step is to size the and deprime the clean cases. Clean cases are easier to size and the depriming will take care of any pesky hole cloggers.
After many years of trying stuff that's not made for case polishing I can tell you the treated shell media sold by Midway USA is the best value.
Pet bedding materials are usually not the correct size. The treated shell polishes and lasts a long time. Corn cobb is softer and doesn't polish like the treated nut shell.
You can get the nutshell lizard stuff but it's not treated....now you have to buy additives and the proper additives ( Rooster Labs polishing additives) is expensive...it eats up your savings...just get the stuff from Midway USA...much better deal than DIY with lizard litter.
Gary

I'm on board with all this, except ....

I've always used the "red" treated walnut, such as Lyman sells. It's red because it's treated with red rouge. I buy red rouge powder for a buck or two an ounce and re-treat the media 2-3 times before tossing it. I also bought some cerium oxide powder( about $10 for 8 ounces) which is used to polish glass....windshields and headlights for instance.

The expense for those compounds is pretty nominal...maybe 50 cents to treat a batch of media that will polish several thousand cases.

Since I'm buying the polishing powders to get the most out of my media, I decided to try some lizard bedding walnut. The combo of walnut and powder additive is pretty much a wash with buying treated media. Both types of walnut do a fine job of polishing with different handling characteristics. I'll use both until I run out and since I'll probably run out of walnut before additives, I'll likely stay with the lizard bedding.

In 50 years of handloading I've never "washed" brass. Guess I'd rather fish than cut bait.

 

[crankyoldlady]

Most of my shooting is in an indoor range. Brass is swept up rather than picked up which increases lead dust. For me, washing dirty range brass minimizes contaminants and keeps my medium cleaner longer.

 

[DumpStick]

Curious here. What is the purpose of the mineral spirits? It seems as if it would counteract the polishing/lubing effect of the Nu-Finish. Like mixing solvents and lubricants.

The mineral spirits thin the NuFinish, and help keep the dust down. About a teaspoon is all it takes.
The NuFinish just seems to work better that way.

 

[Twoboxer]

I used crushed walnut pet bedding plus dryer sheets for dust plus the occasional additve for a few years. Then someone I respected told me that corn cob COULD polish/clean better. It also COULD have almost no dust, last longer, require no additives that add cost and can gook up the works . . . all while leaving nothing stuck in the primer pockets or anywhere else in the brass.

The specific product required is small ground corn cob blast media, 425-1000 micron range . . . like this product: Corn Cob Abrasive Nlasting Media .

You still need some process to separate the media from the brass (I use a rotary separator for about a minute), but the keys are the dust has been lost in the sieving process and the particles are too small to stick anywhere.

Other stuff can certainly be used, but the ones I've used each require some other product(s) to offset the disadvantages.

 

[BigBill]

I decap first, then run the dirty cases in the cob media. I resize and clean the primer pocket. Next it goes in the walnut media with some brass polish for its final cleaning. My ammo looks like new.

 

[Old&Retired]

Personally, I clear all the clogged primer holes before priming. That said you may find this link an interesting read.
Box Of Truth actually did an accuracy check with both clear and clogged primer holes w/ a .223. Very interesting results.
Educational Zone #152 - Does Polishing Media in Flash Holes Affect Accuracy? - The Box O' Truth

 

[stansdds]

Personally, I clear all the clogged primer holes before priming. That said you may find this link an interesting read.
Box Of Truth actually did an accuracy check with both clear and clogged primer holes w/ a .223. Very interesting results.
Educational Zone #152 - Does Polishing Media in Flash Holes Affect Accuracy? - The Box O' Truth

That's weird. I would have thought a clogged flash hole would have caused inconsistent ignition of the powder, but based on group sizes... it has the opposite effect? I wish he had also made a chronograph comparison between the two.

 

[Mike SC Hunter]

It's what you learn after you know it all that counts.