target action in 300 win mag?

I need a little insight here. Want to start a build using the 3 screw target action (orange trigger) but chambered in 300 win mag, now obviously i will have to swap the bolt head to a magnum head and it will only be a single load rifle, which is fine and what I intend it to be (1000yrd prone). Will everything be ok as long as the barrel is headspaced correctly and the bolt head swapped out or am I missing or overlooking something here?

Speaking of this, has anyone built a custom using the target action? and if so, how is the quality, was there any squaring or blue printing that needed to be done? please post up some pics. Thanks!!

you'll have to remove the bolt to eject an unfired round
other than that
just a barrel & bolt swap
& set up headspacing of course
Jim at NSS in the vender section has target actions in stock

Also with the target action you'll use large shank barrels.

I've built numerous custom rifles with the 4.4" single shot Savage Target Action and the DBM Target Action using Hart, Shilen and Douglas barrels. Never built a 300 WM, but did build a 300 WSM and loved it. Every rifle I've built shot 1/4-1/2 MOA(max) after taking the time to work up the proper load. I personally don't believe squaring or blue printing is necessary with the target actions, due to the floating bolt head. I had one done as part of a package and I noticed no difference in feel or accuracy.

Have you considered the WSM instead of the WM? Good luck with your build.