OK I want to build a 300 Fireball or two.

[Krink545]

OK I think a little background might help with some of the answers I get so here we go. I like to build things and if I find myself borrowing things from Friends or having to pay someone else to do some work(and hope they do it right) that I cant do because I don't have the equipment ill eventually end up buy more and more shop equipment. I currently have a Jet 13x40 lathe, a little bench top mill, 25 ton shop press, wire welder w/spool gun, torch set, big blast cabinet and tons of hand tools(was a Snap-On dealer years ago).
I've built many AR's,AK's,RPK's,Krinkov's but have yet to build a bolt gun.
I've also chopped,threaded and re-crowned many barrels.

OK to the builds, I want to build a bolt gun from a used Remington 700 .223 and a 10.5" AR upper to use on my M16A1 and a SBR'ed AR I have.

First some basic questions I see a lot of people talking about their Whispers that I'm not sure are true Whispers. Doesn't a true Whisper require you to use 221 brass sized to 300 Whisper or 223 brass sized with the neck turned down to fit the 300 whisper chamber? What I want to do is use 223 brass sized without having to turn down the necks. What dies do I need to do this on my Dillon XL650? I would trim off whats left of the 223 neck in the lathe or mill than finish trimming them in my Giraud trimmer if I can get a shell holder for it.Next I've look on the Pac-Nor site at their barrels for a 700 and I have seen people talk about 1in8 and 1in6.5 twist rates whats the advantage over one or the other? Also on Pac-Nor's site they call it a 300 Whisper chamber is it? Pac-Nor also list some barrels prefit barrels that are chambered, contoured and threaded for the action, how hard would it be for me to buy one of these and get it done right with the tools I have. I don't have a barrel vise or action wrench yet but their on my short list of things to buy but I do have a guy here locally that builds guns that would let me use his stuff or I could pay him to do it for me. Who else are you guys getting your barrels from?

I for the AR build it sounds pretty straight forward. I'm going to buy a Model 1 barrel plug the existing gas port turn the barrel down and install a pistol length gas system. Then cut the barrel down to 10.5" thread and re-crown.
I'm I missing something?

Thanks for the help.