[HiBC]

This seems to come up every few months.
I did read the part where the OP said brass would not chamber with no bullet seated.OK,sometimes there are multiple problems.

In your picture,It looks to me like the shoulder collapsed and bulged outward.I might not see it right,but I can see it.

Do you run your seating die down to contact the shelholder? If so,that is your problem...at least one of them.Back the seating die away from the shellholder.
Put a sized brass in the shell holder.Raise the ram with the die backed up 4 turns.Now,screw the die body down till you feel the brass with the die..Now,back off 1/2 turn.Set it there,for now.
You might have seen very little crimp.That is because you are not crimping into a cannelure.The case collapses first.

Now,your crimp comparison pix,it looks to me like the neck of the reload on the left is longer than the factory load on the right.It looks to stand slightly higher than the cannelure of the bullet in the right..016 to .020?


Did you measure your brass length over all and trim if necessary?Brass to long will not chamber.

Crimping is controversial.Some do,some don't.If you must crimp,get a Lee factory crimp die.You will get poor results if your brass length varies.It is best to use bullets with cannelures.

If you buy a bushing type gage,an over length neck will protrude and you will know it is trim time.

I do not see a chamfer on the case mouth.I recommend a slight id and od chamfer.

Do you see the shiny ring around the case at the junction of the case body and the shoulder?That is the bulge where the case collapsed.Measure over the shiny ring,then measure just behind it.