M14- reloading for a large headspace rifle 308 edition

[GunNewb]

Since our cheap norinco rifles tend to be chambered for 7.62 mine actually closes on a 308 no go gauge super easily. Using dissasembled bolt, automotive feeler gauges and a clymer 308 gauge I came up with 1.641 headspace- rough idea of where It's at and I will try another method as well later.


For now Im trying to figure out how to reload for such a large chamber using the 308 brass that is available to me. (forget lake city in Canada) 308 is already smaller than 7.62 and my chamber seems large even for 7.62.

So is there a way to set my dies to make the 308 cases work in that roomy chamber or am I kinda screwed? What are the ill effects of putting a casing in the rifle that is over field no go specs..308 FIELD 1.638" vs 1.641ish

 

[rnbra-shooter]

So is there a way to set my dies to make the 308 cases work in that roomy chamber or am I kinda screwed? What are the ill effects of putting a casing in the rifle that is over field no go specs..308 FIELD 1.638" vs 1.641ish

That's exactly what you do.

If you get a "fired case headspace gage" it's pretty easy to do this adjustment. RCBS's "Precision Mic" will make the measurement you need.

Take a piece of brass fired in your rifle and measure it with the gage. It might read "+7", meaning 7 thou longer than nominal zero-headspace for a .308.

You screw down your F/L die until it touches the shellholder, then you unscrew it some - so that when you size a case, it sets the shoulder back a few thou from what your fired case reads. If brass comes out of your rifle at "+7" on your gauge, I'd set up the F/L sizing die to make your sized brass read "+4" or "+5". Be sure to verify that this brass will chamber in your rifle and the bolt will lock up without resistance.