Please give me your ideas and if you neck turn, what tool you are using. I have looked at a number of different tools but their prices range from cheap to needing to put another mortage on the house. Just wanting some feedback and people's ideas.
Interesting question for sure and a little bit complicated to answer!
If your barrel chamber is so tight that a loaded round won't fit because the case necks are too thick then you will need to turn the necks to achieve adequate clearance. This is determined by the brand of brass used and the reamer used by your gunsmith.
If you are attempting to improve accuracy then the theory is that case neck concentricity is improved by turning necks which allows the bullet to be released in a more uniform way.....
For some shooters, particularly short range bench resters, neck turning is mandatory. Many Fly shooters will give the necks a "skim" in order to improve accuracy and others turn necks because their cases won't fit the chamber due to the reamer used to cut their chamber. Some shooters don't turn at all claiming it is an unnecessary and laborious task!
I have a foot in each camp. I turn my 7mm's, 30 cals, 6mm pro cals & ppc, mainly to improve the brass but also to allow loaded rounds to fit. I feel accuracy is definitely improved with these , particularly my 7's and certainly my 30 Wsm's.
I don't turn my 6 Brx's as the reamer used to cut the chambers allows a perfect loaded round clearance with the brass I use which of course is Lapua 6 BR. Also, it seems the quality of this brass is so good that if there are inconsistencies in case neck concentricity they are ironed out when I form the case from Br to BRX.
I now use a 21st century set up including their lathe and power it with a battery operated drill and yes I remortgaged our house to pay for it!