Belted Magnum Headspace

[wmterry89]

I purchased a 300 Weatherby take off barrel for a CRF model 70 to replace a 7mm Mag barrel. In comparing the barrels the 300s chamber is .003" deeper than the 7mm. With either barrel on the receiver, the bolt won't close on the GO gauge, but will close easily on a factory cartridge.

It seems to me that the 300 Wby barrel is good to go without any machining, but I'd like a second opinion.

 

[MagnumManiac]

The headspace on the belt is .220" from base. SAAMI allows .010" over this, so if your measurement is .223" to front of belt, then you're good to go.

I never use a cartridge to headspace off, they're rarely ever .220".

I set my belted mags, when chambering, to exactly .220", saves any drama when loading cartridges down the track.

Cheers.