38 Special case expansion

I am curious if any of you shooters of 38 Special in a semi-automatic have observed any unusual case expansion, compared to revolver cases.

How sloppy does the chamber have to be to facilitate flawless functioning?

My recently fired cases have expanded to  .380"   , mostly on one side. Neck is about .376.
Resized to .375.

I should investigate if the extractor or slide is forcing the case to one side.

Thanks.

Which semi auto? Model 52 smiths are not supported at the rear chamber ramp and may bulge there. I do see more expansion than in revolver cylinders...ie 52 brass will not chamber in my k38. Have to verify the measurements. More later

Giles, built from 38 Super slide and barrel, bushed chamber for 38 SPECIAL
Receiver 132, xxx

I am not concerned about the chamber on my M-52, even if partially unsupported. The mouse fa** loads I use (2.8 gr Bullseye) are low pressure. I have not tried to chamber my fired brass in a revolver but resizing them with carbide dies is easy.