Of course the 300 PRC would also be a considerably long round with a 230 seated in the neck.
I have a 338-375 Ruger and to get the 250gr Berger HVLD bullets seated up in the neck properly while touching the lands and still fitting in a magazine, I had to install the largest Rem 700 Wyatts extended box there is. The CFE-9. Took a lot of work. Had to mill out the stock, mill the bottom metal and move the floor plate release spring, mill out the receiver magazine port, re-face the mag port feed lips, modify the bolt stop so it cycled further to the back of the new longer mag, and mill out the ejection port so a loaded round could be ejected. It was a pile of work to get the round to feed from a magazine with the bullet seated where it should be. But it was worth it in my opinion. Would I do it again? HELL NO!!! Pain in the a**! LOL.
...And this action was already set up for a Remington Ultra Mag. My 338-375R loaded round OAL is 3.745" and that's what it took to make it work in a repeater with the bullet seated where it should be. Will also work in the mag with 300gr Bergers seated to the lands.
The rifle was very accurate prior with the bullets jumping a long ways to the lands, but the loads were touchy. Didn't ladder test very well. Now with the bullets allowed to stay in the neck it is more accurate, more forgiving and consistent, and I have more case capacity to work with. Win, win, win.
Milled ejection and mag port with new bolt stop location
Modified floor plate release spring attachment point