Brass much thicker right by neck?

bigedp51 said:

It doesn't matter if you wet tumble after every firing or wet tumble after the 5th or 6th firing.

Every time you wet tumble the case mouth is peened, and the longer you wet tumble the more the case mouth will be peened.

This is why I trim my cases to minimum length every time I wet tumble and cut off the peening and the thicker case mouth. This isn't rocket science and I can't believe some of the answers given in this posting.

The OP wet tumbled his cases four hours and pounded and peened the case mouths, end of story, trim the cases and fix the problem.

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You're exactly correct, and the answer is exactly what you're doing.

I never tumble using the steel rods and wet media. The rods pound the brass and work harden it as it tumbles. I use a vibrating tumbler, either walnut shell or corncob media and liquid brass polish. I still get a little case mouth peening, but its minimal and removed when I trim and bevel the case. And I always put a slight bevel on the case mouth so the mouth won't shave any gilding metal off the bullet. You need to remove any excess from the inside of the case mouth when you trim the case anyway. It just makes the bullet go into the neck more smoothly.

Why does wet tumbling cause this and for that matter what is wet tumbling? I only dry media tumble i guess, other than brass cleaner I don't get them wet.

Its not the wet tumbling per se. Its the use of the steel rod media in the wet tumbling systems on the market. you're tumbling your brass in a media that is much harder than the brass. Its like bouncing little steel bbs off the brass for an hour or two. I use the soft medias and a liquid brass polish which I add a couple of cap fulls of into the media. Corn cob or walnut shell is much softer than brass, and just applies a thin coat of polish and then removes it as it vibrates across the brass. It won't work harden the brass. There's just enough brass polish in the media to clean the brass, and the only impact is between the casings themselves, which is minimal.

greenejc said:

Its not the wet tumbling per se. Its the use of the steel rod media in the wet tumbling systems on the market. you're tumbling your brass in a media that is much harder than the brass. Its like bouncing little steel bbs off the brass for an hour or two. I use the soft medias and a liquid brass polish which I add a couple of cap fulls of into the media. Corn cob or walnut shell is much softer than brass, and just applies a thin coat of polish and then removes it as it vibrates across the brass. It won't work harden the brass. There's just enough brass polish in the media to clean the brass, and the only impact is between the casings themselves, which is minimal.

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Do you recommend a particular brand of polish, and how long do you leave them in the tumbler ? I have one of those vibratory brass cleaners. In your experience, is that as good as a tumbler ?

Mine is a vibratory brass cleaner. I use the lyman brass cleaning solution. I leave them in for about 2 hours, and check to see how clean they've gotten. I'm not looking for shin brass, just clean brass. About two to three cap fulls puts enough into the media to assist in cleaning.

So then tumbling with steel rod medium would be work hardening the entire case to an extent ?

DSheetz said:

So then tumbling with steel rod medium would be work hardening the entire case to an extent ?

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Wet tumbling does not work harden the brass, and the case mouth peening is caused by the cases hitting each other and peening the case mouth. Go back and look at the photo I posted and the right hand case mouth. That case was "DRY" tumbled at the factory and was beat up more than the wet tumbled case. Tumbled cases are rotated in a drum like a cement mixer wet or dry. And a vibratory tumbler merely vibrates the media to clean it.

Any case cleaning method has its good points and bad points. And wet tumbling with stainless steel media does a fantastic of cleaning the cases. "BUT" the longer you let the tumbler run the more the case mouth will be peened. And the faster the rotational speed of the tumbler the further the case will fall and hit each other. The secret to wet tumbling is to not overload the tumbler with brass and the cases will be cleaned faster with far less peening.

I also find it very strange that someone that does not have a wet tumbler is giving out advice on wet tumbling.

Very interesting they both look almost the same to me .

I don't own one because I don't need the shiney brass. I just need it cleaned. And metallurgy 101-any time a harder metal bounces around against a softer one, you will get work hardening. I know case mouth peening is from the cases hitting each other. I've been doing this for over 50 years. However, any case hardening caused by the steel media is a moot point, since the case neck of the cartridge will have failed or case head separation will have begun long before the very minimal case hardening of the body of the case has had an effect. Annealing will help with case neck cracking, but case head separation is something I haven't seen a fix for. If you've got one I'd like to know what it is. I just use a vibratory because I am cheap. I don't want to spend the extra money for the system. I'm cheap, cheap, cheap. Also, if it works, don't fix it. I don't think its a bad system, I just don't want to spend the extra money when I could spend it on a new 35 Whelen custom Remington 700 with an E.R. Shaw 1 in 14 inch twist 26 inch barrel. And its in the works right now, along with the mounting of the P2 Shepherd scope. I have several friends that have the wet system, though. It works pretty good.

DSheetz said:

Very interesting they both look almost the same to me .

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Well they are. One gives you really shiney brass and is messy, one gives you duller clean brass and is messy but cheaper to use. I'm cheap. I only do what I have to to make my brass load and shoot well in my rifles. I have more things I can do with my time, like shooting the rifles at prarie dogs. Going through some of the stages for prepping brass is time consuming. So I only do what I have to, and I spend the extra time loading the brass and (the fun Part) emptying them at critters and targets. My loads tend to shoot under an inch with the level of brass prep I'm already doing, so I think that's good enough to let me get out and shoot.

DSheetz said:

Very interesting they both look almost the same to me .

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When wet tumbling the water hardness and the amount of dish washing liquid effects the cleaning time.

And again if you like wet tumbling and very clean cases the fix for case mouth peening is to trim your case each time you wet tumble. The OP tumbled his cases four hours and this is what caused his case mouths to become thicker.

At the other end of the spectrum is sonic cleaning that does not have the cases hitting each other but the cases are not cleaned as well and have far less bling.

I started wet tumbling when I got firearms that throw perfectly good brass away and and makes you go look for it. The ejected cases would hit the ground and pickup dirt and grit and scratch the brass and dies. And wet tumbling would scrub the cases clean of the embedded dirt and grit. This was not a problem at the range with my bolt action rifles and revolvers.

bigedp51 said:

When wet tumbling the water hardness and the amount of dish washing liquid effects the cleaning time.

And again if you like wet tumbling and very clean cases the fix for case mouth peening is to trim your case each time you wet tumble. The OP tumbled his cases four hours and this is what caused his case mouths to become thicker.

At the other end of the spectrum is sonic cleaning that does not have the cases hitting each other but the cases are not cleaned as well and have far less bling.

I started wet tumbling when I got firearms that throw perfectly good brass away and and makes you go look for it. The ejected cases would hit the ground and pickup dirt and grit and scratch the brass and dies. And wet tumbling would scrub the cases clean of the embedded dirt and grit. This was not a problem at the range with my bolt action rifles and revolvers.

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Thoroughly agree. And I also have several firearms which refuse to drop the brass into my hand, but insist on throwing it every which way and making my old tail work to collect it. My buddie's M1A and my H&K 91 throw brass 7 or 8 feet in nice large patterns. They're a pain in the tail to re-size, too. Especially the H&K. I never tumble more that two hours. They're either clean by then or they won't come clean. But I have a public range near me where I can get brass for nearly everything I shoot free or at only a few cents per casing. Its once-fired, but I resize it in a FL die and most of it is usable.

How to clean your brass for reloading with Jerry Miculek


Jerry Charles Miculek, Jr. is an American professional speed and competition shooter known for his many world records, appearances on TV, and internet videos.