Ultra sonic cleaning changed brass ???

steve123

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Mar 16, 2008
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Upon 3 firings I decided to do an ultra sonic clean on my 6mm AR Turbo.

I full length sized the brass and ultra sonic cleaned them extra good/long to get all the carbon out of the insides.I used a 1/2 water and half vinegar solution with a squirt of dish soap.
I let em dry and loaded them up.
So of course!! I'd have to discover this while shooting Scottmilk9's tactical match in Phoenix yesterday.The darn rounds were sticking hard in the chamber.I could hardly pull back the carrier and some barely went in also.
I took the same offending brass "fired now" and sized em up,checked em in the chamber and they fit fine again.I know without a shadow of a doubt that I tightened the die down because I always use a crescent wrench to tighten it.I can only conclude that the ultra sonic cleaning altered/annealed/relaxed,did something to the brass to change the dimensions of it.

Any one have this problem before? I guess I'll resize after cleaning from now on.

Steve
 
Re: Ultra sonic cleaning changed brass ???

Maybe it was so nice and clean and completely free of dirt/oil/lube that they stuck too well? If you got all the scale off the outside of the case and exposed nice fresh brass to the chamber walls I bet it would stick like glue compared to the old ones.

New brass that's been tumbled and polished and cleaned up with an alcohol wipe sticks pretty good, but it's back to normal on the next firing for me.
 
Re: Ultra sonic cleaning changed brass ???

That's a thought but I think not because...They were super tight in the chamber like "as if" the previous firing was a max load and they were only neck sized.It's a pretty bizarre thing?Oh and also all the brass was the same exact load.

I cleaned three batches of 50 and the last batch of 50 needed a couple more cycles to get completely clean.This one sticky batch was being cleaned for prob 2hrs total vs 1hr for the other two batches of 50 which fit in the chamber fine.As a matter of fact I used them Saterday at LVshooters match and the gun and ammo functioned flawlessly.

I'm cleaning one more batch right now and am going to run them for two hours also and see if I can duplicate the problem again.

Steve



 
Re: Ultra sonic cleaning changed brass ???

I only US clean my brass and have never had any issues and I only necksize. I have brass in variety of calibers necksized 7+ times. I use Citranox. Hope you find the answer!
 
Re: Ultra sonic cleaning changed brass ???

The brass even feels sticky after US cleaning. I decap, clean, prep and then run
through the tumbler to smooth it back up. I think it's just etched a little from the
vinegar and is rough not sticky.
 
Re: Ultra sonic cleaning changed brass ???

Steve

I've been ultra sonic cleaning for a couple of years now and have never had that problem. I switched away from vinegar to a commercial cleaning agent at least a year ago, which turned out to be much less expensive - I bought it by the gallon and am less than 1/4 through the gallon.

It looks like you are not doing anything to neutralize teh acid in teh vinegar, and that this may be causing your problem by doing a bit of surface etching on the brass (as noted above me somewhere). You likely need to do something to turn the acid in the vinegar "off", and your problem may go away.

I full size w/ a 0.001 to 0.0015 shoulder push every round, including my F-Class rig.

Unless your cleaner has super heating capabilities to get the brass over 380 degrees, its not an annealing related issue.

JeffVN
 
Re: Ultra sonic cleaning changed brass ???

I tried to duplicate the same conditions with a 2hr clean and they were a little sticky but not bad.So I'm puzzled.Maybe a little piece of debris got in between the lock ring and press for that batch.I don't know.The heater in the US only heats to about the same temp as hot tap water.

Can you tell me what solution you use to neutralize with?

Steve
 
Re: Ultra sonic cleaning changed brass ???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steve123</div><div class="ubbcode-body">Can you tell me what solution you use to neutralize with?</div></div>

Steve,

You and I were talking about this on Sunday, and I've been thinking about it since. I'm not sure that a surface etch will cause the type of "jam" that you encountered, as I remember you really having to work on them. It wasn't windy, nor were we running through the hills so I'm confident in ruling out the dirt/debris in the chamber. And we were under the pavilions so the ammo was out of the sun and cool. I'd look more into the locking ring obstruction you were speaking of.

As far as nuetralizing the vinegar, Birchwood Casey Case Cleaner is what I use. According to Jason Baney over at 6mmBr, this will counteract the vinegar and is readily available.

Nick
 
Re: Ultra sonic cleaning changed brass ???

Hi Nick,

Thanks for the tip.I just need to break down and order some Birchwood.I haven't done much US cleaning and have put it off.

I screwed the size die down a tad.Hopefully that will take care of the problem.I'm gonna check each batch to make sure there are no problems.Just caught me off guard since I hadn't had that problem before the US cleaning.

Steve

 
Re: Ultra sonic cleaning changed brass ???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: steve123</div><div class="ubbcode-body">I

Can you tell me what solution you use to neutralize with?

Steve </div></div>

Baking soda.
 
Re: Ultra sonic cleaning changed brass ???

I can absolutely vouch for Citranox as well with my US setup. Much more effective and cheaper than MPro7 or Simple Green or a Vinegar solution.

I bought my gallon a year ago and still have a ton left. You only need a 1% solution of Citranox to water so the stuff goes an incredibly long way.

Here is where I bought it. Good pricing and quick shipping:
Pollards Water - Citranox