Casing marking

Not a hand load. Hornady SST 130gr 270. Shell casing has a flat spot on the bullet end after fired. Cause?

I'm assuming you mean the neck of the case. Could be something in the chamber. Clean it.

Yep start by cleaning it making sure nothing is in chamber causing flat spot.not real likely to have a bad cut chamber since reamers cut in a circle

Pic coming

Looks like it's getting dented from extraction.extractor pulling it to side and it's banging on action coming out reciever?
Watch the case come out slowly to see

My guess too.

Yep

What they ^^^^ said

What they said. If it is happening when you are chambering a round most likely you would never be able to close the bolt. Or, at least it would be very stiff closing the bolt. Looks like an extraction issue.

I had a BAR auto that did the same thing. I assumed it was something about the quick unloading sequence of autos that did it? Bought the gun brand new and the first case that was fired through the last case that fired through it looked exactly like that.

What they said...

Was gonna say looks to have been fired from an automatic

My Garands and FALs do the same thing except 5x worse. I have to use an expander to round them back so they can fit in a sizing die. As said semi autos do that almost every time. Full power semiautos are rough on brass. I've found out that maybe five reloads are the best to hope for. Every time I reload for the semi autos I use a dremel tool and cut a small notch in the case rim. Four notches means five times fired. Time to go to the brass bucket. Usually the primer well has expanded on most of them by then. Loose spent primer parts in a semi auto action can cause surprising results.

Fire a round and slowly open the bolt and slowly slide the bolt back keeping the case from ejecting and see if the neck is flattened then. If it is then take it to a gunsmith to have it checked.

I shot the gun afterwords and didn’t notice any thing wrong with the casings, my FIL bought the gun new and hasn’t been
fired a whole lot of times. It is by far the smoothest bolt I have ever worked and has been in the gun cabinet for 15 years.
Win. Model 70 270 I prolly bolted to hard expecting it to be not so smooth and easy...