Anyone neck-sizing only for 458 Win and/or 45-70?

[tacotime]

I was late getting the info that neck-sizing only should be better to preserve my brass.  

Is anyone neck sizing only their 458 or 45-70?

I don't even see a neck sizing die for 458 on Midway, and 45-70 choices are limited.  Is neck-sizing uncommon on straight walled cases?

Thanks.

[shot1]

I use a full length size die to only part size my 45-70 cases. It really only sizes the neck area so it will hold a bullet well. My chamber is a little sloppy and it just shoots better with the part sized cases. I shoot black powder and cast bullets.