Ultrasonic brass cleaning and case life

[44hunter45]

Setup:
Some time ago I bought some 264WM "once fired" brass on GB and they were absolutely spotless. Too spotless. Every time I buy rifle brass used, I anneal it. In spite of the anneal, I lost more than 75% of the cases to neck splits when I sized them, lubed inside and out.
I got back to the seller and he said they were ultrasonic cleaned, and good brass. He contended that the problem was my process. I trust my process.

Question:
Does ultrasonic cleaning work harden brass? Even if it did my annealing should have alleviated at least some of that.

 

[MThuntr]

what cleaner do you think he was using? If it has any ammonia in it that could be a cause. I wonder if he used Brasso (makes brass super shiny but contains ammonia)

My uneducated guess would be you bought junk brass and I'd wager they were fired a lot more than once. Split necks with once fired and annealed is a tough sell.

 

[44hunter45]

what cleaner do you think he was using? If it has any ammonia in it that could be a cause. I wonder if he used Brasso (makes brass super shiny but contains ammonia)

My uneducated guess would be you bought junk brass and I'd wager they were fired a lot more than once. Split necks with once fired and annealed is a tough sell.

Yup. I've bought and sold a lot of brass on GB without issue. This is the only seller I've ever said I would not work with again. I've since decided I will only buy "ugly" brass as well. Case prep is part of the fun for me.

 

[Gut Shot]

Mthunter is probably right, it was probably a chemical issue, not a cleaner issue. Tumbling in steel shot will work harden stuff but I've never had things harden in the cleaner.

 

[EastTNHunter]

Ammonia and brass don’t mix. I know people that want their brass to look pretty and use Brasso or other additives to their tumbling media. It won’t (can’t) last as long.