I was running through my first-in-a-while batch of .38 Special with 148 grain bevel-base wadcutters, and ran into a problem with my already-prepped and sized range brass.  My sized CBC cases were not giving me much, if any bullet tension.  After culling these cases out of the rest of my 100-round batch, I stuck the sizing die back into the Lock N Load's die deck and ran these cases through again.  I got maybe "marginal" tension with a second sizing.

I am not over-expanding the cases.  I'm using a .357" powder through expander that frankly isn't expanding enough for these bullets since I'm getting plenty of lead slivers along with the expected excess lube floating around.

Has anyone else had issues with CBC brass being thin or otherwise hard to size adequately?  Unfortunately I have at least 55 more of these cases that I'm wondering what to do with....

I have quite a bit of 38 Special CBC brass in rotation.  8X loaded at the moment, but they are fairly light loads.
Haven't had any trouble with the brass.

Interesting.  Maybe I hadn't "processed" those cases as much as I'd thought...

You have got one of 2 things going on there.

1) The brass is more springy than usual.

2) The brass has thin walls.

I'm guessing it's 2) The brass has thin walls.

Motor

CBC is Mag Tech, so should decent brass.
There are couple questions what kind of bullet it is? Home Cast and Size?  Commercial Cast?
Do you have a Lee Carbide Factory Crimp Die it essentially is a sizer die.  Perhaps if you did you could run the brass through that and expand the
case mouth again?

The belling operation is an easy fix, just turn the powder die down ever so slightly. It just means the CBC are slightly shorter in OAL.

How many rounds have your dies sized in their lifetime? Do you use any lube or do you run them dry? I know it takes a long time to wear dies out, maybe yours are nearing the end of their lifespan. Maybe they were borderline straight from the factory. You can easily measure the case wall thickness by comparing the loaded CBC brass to the loaded rounds using other brands. I would be surprised if there was more than  .001" or .002 difference..

I have a friend that shoots high power tournaments with me, he's much more active than I am. He has worn out .223 sizing dies out before. I never have.

I sort out foreign brass and use it solely for blasting ammo. I keep Federal and Speer as my Tier 1 brass when loading handguns. Winchester and Remington is Tier 2. Everything else is for blasting ammo.

I like IMI pistol brass but will keep it in Tier 2 or blasting status because I don't get it in the quantities I consider useable. Geco, IMI, Sig, Fiochi, CBC, Seller & Bellot, Arguillo, Hornady, Extreme and any other oddball brand except A-merc (which gets trashed) get used for fun, not competition or self-defense. I simply get too few of these cases to mix them in with the large quantities of good brass I normally get. There is nothing wrong with any of these as far as I can tell, I just have the volumes that I don't need to mix them in with the brass I like the best.

Once fired brass purchased at .04 cents +/- each just isn't worth worrying about. Free range pick-ups even less so. Just chuck them if they are causing you any trouble at all.

Considering that we're talking about 38spl unless it's a steel die I don't think it's worn. You would have to size a whole lot of dirty brass to ever ware a carbide sizing die any.

Another thing to consider is the fact that most expander's size for about .003" fit. So if you measure .002" difference you are down to .001" fit.

The point I'm making is it doesn't take much. A little thin on case wall combined with maybe a sizing ring made on the high side of the tolerance and things add up.

Motor

I think I found the issue.  These cases were from a more recent range trip than the bulk of my other .38 range brass.  I used an old version of the label I use for keeping track of processing, and I may have simply skipped the sizing step because the old label said "prepped" instead of "cleaned...sized...de-lubed" as the new one does.  

I have these cases separated out, so I'll play around with sizing them and see if I was just lax in my labeling.

That's a very good observation for anyone who de-capps and cleans then stores for later use. It would be hard to tell if they have been sized or not.

It's funny how many times we cause our own problems.

Motor

Yep, I hadn't sized these cases.  They weren't as smooth a fit in the cylinder of my Model 19, and running a few into the sizing die gave me the kind of resistance you'd expect from fired cases.

I need to go through and check all of my labeled containers, and get rid of the old labels.

Thanks for the thought and input, folks!

Today, I loaded the CBC cases I'd separated out.  They were just fine.  In the process, I verified for myself that sizing during the progressive loading process causes a lot more vibration of the whole press than just the actual loading process.  For .38s that's not a big deal, but some cases are really a problem.

I've rechecked all of my labeled containers.  In the process I consolidated some smaller containers of brass, notably .32 Auto.  I have a large quantity of these little guys, and they're now all partying together instead of all isolated and alone.