300 winmag headspace

I installed an ER shaw barrel on my 110 and I don't if its how the threads where cut or what but ever time I tightened the barrel nut the receiver tried to turn also. I had the barrel in a vice with wood blocks which held well and my friend held onto the receiver but it would always turn before 70 ft lb.

I was using a forster headspace gauge and took it out before I tightened the nut but apparently the receiver moved a little as when I got home the bolt wouldn't close on a headspace gauge but it will close on the factory loaded Federal and Hornady I have.

So apparently a headspace gauge allows for a couple thousandths gap between the shell and bolt since most factory ammo is under max spec. I confirmed that the bolt will not close on an empty brass with two pieces of tape or a .004 beer can shim.

So my question is would this be safe to shoot? I would rather not have the extra play the headspace guage would allow and would think you would see better accuracy since the bolt just kisses the cartridge and there is no room for play. And since all rimmed ammo I have seen has consistent belt to rim thickness I shouldn't have a problem loading most factory ammo. But either way I will be sticking with one brand of brass and just necksizing or bumping the shoulder back .002 tops.

I would reset it with the headspace gauge. Using the gauge is not sloppy. You didn't say whether or not it was a Go or No-Go gauge.

I used a go-gauge. It says .220 on the side but the rim to belt thickness on my ammo is only .215. That leads me to believe that if set correctly there will be .005 for the shell the move back against the bolt when fired. It seems like it would be more accurate with minimal space between the rim and bolt head but you might have trouble loading certain brands of ammo of it the gun gets dirty.