Re: RCBS Competition Seating Die
I know this is an old thread, but did a search and found this as I have the same problem with excessive bullet runout using the RCBS Competition bullet seating die with AMAX bullets. Specifically with the .308 dia 208 AMAX I found the bullet does not fit the seating plug and the tip bottoms out in the plug. However, I found a technique that seems to solve the problem.
I substituted the next size smaller RCBS Competition Seater Plug Assembly for the one for the 30 cal, in fact I used the 7mm seater plug and this seems to work fine, it fits the bullet point much better if you fit it by hand before you install it in the die and my bullet run out is back to normal with this type of die.
In fact if you use the RCBS Competition Seating Die, I have substituted the seater plug and bullet guide on my die and used it for other cartridges with good success, although sometimes for the shorter cartridges you need to get the extended shellholder as well. I think the RCBS Competition Seater body is a generic part with the cartridge specific parts inside which you can switch out if you so desire to use this for a different cartridge.