Which comparator insert.

[Turpentine]

I mostly agree with this apart from the .223Rem/5.56. The Hornady bushing is really close to the case body and I've wondered if that's the best place to measure?

Sorry for any thread deviation. I realize the cartridge discussed is not the same.

So many people get wrapped around the axle about sticking expressly to the topic referred to by the OP. I'm not one of them. I appreciate your info as I load quite a bit of 223/556 as well and it's all about learning for me Even though I've been loading for what seems like forever. I'm glad you included the information. Likewise the .400 was sitting a bit high on the shoulder near the case wall of the 65-06 and is what drove me to ask this question.
Again guys, thanks for all the answers.