Ok a few points to cover here.
For accuracy in the bolt action Savage I wold recomend keeping the brass for it seperated from the AR brass if you neck size for it. With necksizing you will probably see a noticable gain in accuracy when you find the right load. (I own a savage Mod 12 LRPV with neck sized hand loads it will shoot 6 shot groups that measure .385 inches from outside corner to corner when I do my part. Load is a 68 grain HPBT Match bullet loaded with RL15, and CCI small rifle primer.) My plinking loads for that rifle group a half inch or better on a crappy day.
For the AR Full lenghth resizing is required with each loading. Use your calipers, or a case length guage to keep an eye on brass length.
With .223 Rem if you are not loading for matches, or depending on loads to cash a check to eat on I would not worry about spereating brass. With FL resizing the case mouth will eventualy develope a split. At that point toss the brass. The good part of .223 is so many people at the range leave the brass for it.
Fancy expensive dies are not required to get accurate ammo. A Lee Deluxe die set will do what you need. Use that money that would have bought the expensive stuff, and buy components, and range time. The man on the trigger is more important to accuracy than any die, shell holder, or piece of reloading equipment made.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.