22lr Bizarre Case Mouth Deformation & Diagnosis

[SayNo2NWO]

The pic shows several shot brass cases of CCI Quiet out of a Marlin 795. It only seems to be happening with this particular load, other loads seem to function and look normal. No other problems noticed, feeding, firing, ejecting fine. Plenty accurate still.

I have to manually cycle this low power round and it seems to be happening inside the chamber since I'm pulling the bolt back very gingerly and the case comes out already deformed. This is happening fairly consistently, but not 100% consistent, sometimes they come out looking normal. When I hold the bolt from moving back during firing and then pull back to eject the spent case, it comes out looking normal. Bizarre. I'm trying to determine what the heck would be causing this very weird looking, intermittent and load specific deformation? Any ideas?

[DesertDave100]

Looks to me like the case partially ejects then the bolt pushes forward deforming the case against something, like a feedramp, but the case then goes back into the chamber.

Full power rounds would just eject the case clear.

I don't own a Marlin so I am just guessing.

[SayNo2NWO]

Yup, that sure does make sense and I suppose nothing to worry about.

[mach]

I love CCI Quiet out of my bolt but it sucks in semi autos and the Freedom HUSH is a way better round that will cycle and is quieter