Small base sizing once fired 67LCNM?

[Glenn Powell]

I spent over an hour at the gun shop sorting 200 pieces of .308 67 Lake City National Match brass out of a pile of 66/67/68 stamped brass. I picked the 67 because they were the easiest to spot, 66 and 68 look a lot alike :-\ . Should I run this brass through a small base die before I start all the brass prep voodoo? The fella I got this from used to run an M1-A for competition, and I will be using a bolt rifle. The brass is super clean, with miner dings from ejection and dose not appear to have sized, but dose have primers removed. Thanks, Glenn.

 

[Dans40X]

Your bolt gun chamber will answer that question for you.
S/B sizing may be required if fired from current production SAInc rifle chambers.

That LC '67 NM brass lasts & lasts & lasts even if fired through a gas/piston M1A.

Weight & internal volume differs from current production/military brass,so download by 2gr & work up.

 

[firearmdoc1]

Try full length sizing them and see how your bolt closes on a few cases, If it closes without any trouble don't bother with the SB die.

 

[Glenn Powell]

I won't be getting my rifle back for at least a month or two . So I can't check to see if they will work. Right now I am just trying to get all my ducks in a row so when it dose get here I am ready to go out and have some fun . Thanks for the responses fellas, I guess I will just run em through a standard full sizer and start brass prep.

 

[Hummer]

Get a good 0-1" mic and measure your cases .200" up from case rim. Fired cases should be in the .471-.473" range.

Run case in you FL die and it should size cases to .469 range and no smaller than .468" as that is the factory dimension on unfired M118 Match brass.

On commercial 308 it will run .465" so sizing it to .469 will do just fine.

I have never had to get nor have ever owned a SB die. I have had to trim the bottom off about 1/4th of my dies as they are chambered too deep and won't bump the shoulder enough to allow bolt closure.

I would highly recommend a MO GAGE from Mo's Competitors Supply,Deerfield, Conn. so you will know exactly where your die is moving your shoulder. All you need do is bump shoulder back .001" and bolt will fall shut.

for instance you fire a case, put in in MO GAGE and it says your shoulder moved .003" forward. Start sizing the case and running in MO GAGE till you see it is measuring +.001 or +002" which makes for long case life.

 

[Cold Bore]

I spent over an hour at the gun shop sorting 200 pieces of .308 67 Lake City National Match brass out of a pile of 66/67/68 stamped brass. I picked the 67 because they were the easiest to spot, 66 and 68 look a lot alike :-\ .

You do know that 68 and 69 were the preferred years for brass, much like picking a fine wine, right? They used the 67 production to iron out all of the problems.

I use lots of 7.62 Match brass. Very nice stuff, and like somebody mentioned, it seems to last forever.

As for SB vs FL, I'd definitely start with just FL. You can do all of your prep either way while you wait for your rifle. Very few chambers are going to require SB sizing. Guys do it mainly to ensure that it will reliably feed through a gas gun, not something you need to worry about in your bolt gun.