Due to an excess of of stupid I found that I had dumped three loaded rounds into the drum of my wet tumbler by mistake. I was doing a whole day of brass prep so decided that I'd chuck them in with the next batch to do a pointless test and see if they'd survive two half hour spins with the solution and media and still work. Popped them in the pockets of my shorts and promptly forgot about them so they took a spin in the washing machine the next day.
I was properly chuffed when I shot them out at the range yesterday when all three worked fine. I'd already taken down my chrony so didn't get velocity numbers unfortunately but they felt fine for what that's worth. These were 38 Spl and 9mmP sport shooting fodder in many times fired cases and were not specially sealed.
An interesting and utterly useless thing to have found out.