Originally Posted by birddog67
I neck size then after 5 loadings FL size , nothing wrong with RCBS but , I FL sized some 1 shot cases for my 308 ,
5 with the RCBS FL die
5 with my redding FL dies
Checked the runout at the neck
RCBS was .005
Redding was .003
When I load with the RCBS after seating bullets are from .005-.008 runout
Redding are .002-.005 runout
This is just my experience
Lets dissect that a bit. You say the RCBS is 0.005 and the Redding is 0.003. Thats actually TIR (total indicated runout). your actual off center is half that or 0.0025 for the RCBS and 0.0015 for the Redding respectively. One, thats most likely well within the TIR for a factory bore and two, taking into account the components themselves and your indicator (which I presume is not tenths indicating but instead thousanths indicating, your runout is conjecture.
It's very difficult to measure in tenths with any factory made jig with component parts in a reloading bench scenario.
Not saying you can't, what I'm saying is the procedure isn't consistent. Too many varibles...... and...
Unless the projectile is crammed into the lands (throat of the rifling) upon loading (which is pretty much impossible because the bolt won't close), the 'jump' from the case neck to the lands is, in fact air space, so any small amount of initial runout will be offset as the projectile seats in the throat and begins it's trip down the rifling.
What I'm saying is that 2 or 3 or even 6 or 7 thousands is inconsequential in the grand scheme of things and measuring inconsistencies due to human error and the measuring jig itself, degrade the validity of that measurement.
You can massage your cases as much as you want to and reduce the initial runout to nil (if possible) but you still are dealing with bullet jump, bore runout, barrel to chamber fit and even your shooting style which all contribute to the tound not going exactly where you want it to.
I found myself that RCBS dies tend to have the expander ball assembly seat in the die offcenter from the factory, and easy fix that takes some time and patience on your part. It has to be manulipulated a bit and retightened more than once. No biggie.