Originally Posted by bucksnducks
When reloading for .223 and .308 to be used in semi-autos like the AR-15 and M1A, is a full length resizing die adequate or should a small base resizing die be used? Thanks.
In my case I have a couple of 'true' 5.56 chambers (A Colt and a Sabre) and one Wylde chamber that doesn't like brass that's come out of the other two. LTC Liwanag (former Army AMU commander) steered me to my current reloading process, which is to run all the brass through a Redding neck sizing die and then through a Redding small base die (no crimp) and my problems with the Wylde chamber went away. By using this system, I also work then brass slightly less than if I was using the Dillon "all-in-one" Decap/Neck/Size die overall.
Later, I got a 5.56 chamber reamer from Ned Christenson and 'fixed' the Wylde chamber and my brass issue went away. I still use small base die simply because I feel that the Redding die is more consistent and does a better job than the stock Dillon die.
Short answer: For me, if my brass goes thru an semi-auto rifle, I small base die size it.
Hope that helps.