I've noticed that my seating die consistently deforms my bullets during the seating process (see pictures). I've read that the seating die stem can be replaced to accommodate different bullet types, but I'm not sure how to tell which stem to buy, or whether it will work with my dies.

Has anyone seen this problem before? Any stem recommendations for this type of bullet?

I'm using Lee carbide dies and the bullets are nosler sporting handgun 158gr. JHP.

https://imgur.com/a/VvKEiBd