Collet dies or full sizing

[Andy]

I partial F/L size enough to push the shoulder back 2-3 thou (usually sizes about half the neck in doing so), and then neck size with a Collet Die.

You can make a neck-sizer for the 577-450 using existing F/L dies of the right base diameter. You might have to play around a bit, but I've used a 43 Mauser F/L die and with the bullet sizes I employ it works well. If that's too loose, try the 45-70 and if that's too tight, try the 45-70 seater die.

 

[AP]

Finally, pulling that ball back through the case neck will cause it to stretch

YES!!! Absolutely and very seldom understood! I have read countless times where folks thought their brass was stretching, flowing forward due to pressure -- it was ... but not from the propellant.

And exploring some of the reasons why the expander ball does this is informative. But ... it occurs to me that anyone that speaks in 'absolutes' regarding reloading just hasnt gone down the dark road long or far enough. But I suspect there are some "boffins" buried in the depths of various Ordnance Corps that certainly have great flashlights!

 

[doc25]

I neck size in rifles I use the most. Simply because I find it a PITA to lube and then clean the lube off. I do not run max loads. I also download some of my rifles, 223 to 22 hornet velocities for example and think maybe mistakenly that it would be better to have the brass closer to chamber size for this. I have no scientific data to back this up other than the first point of lubing being a PITA.