Opinions on my mistake

I made a mistake setting up my 3006 die. I have pushed the shoulder back too far on about 200 pieces of brass. I'm about .006 shorter than a standard LC 69 M2 ball round and around .010 shorter than my chamber. The brass is LC 67 match once fired. I began working some loads up with the brass and began getting some primer back out. No leakage or piercing noted. The brass I fired showed 2-3 thousands of stretch, and 0-6 thousands of primer back out.I have since properly adjusted the die.
Are firing these dangerous? Should I scrap the lot?

It's not dangerous but it's going to play h*ll on your brass. It happens, and if you use it for pounders you will still acomplish something, except for the post ammo let down.

For the .30-06 cartridge Ordnance allowed a minimum cartridge length which was .006 shorter than the maximum allowed cartridge length. Of course that was the absolute minimum, and probably few cartridges were loaded that short.

After he fireforms the brass would it help to anneal them? Maybe this would give more life to them?

Maybe he should anneal before fireforming, this may stop the brass drawing too much and stop any splitting.

If the RIM of the casing is held securely by the EXTRACTOR, you should have no troubles, friend.

If I had this problem, likely I would just shoot the stuff.

To be perfectly safe, though, if you have a bolt rifle and a semi-auto, if the bolt rifle is a Mauser type (Springfield M-1903 type, M-1917) then you shoot this off through the bolt rifle and there should be no problems. Hatcher had a lot to say about this. Check his book, chapter on HEADSPACE. Nice thing about Mauser-type bolt rifles is that you can SEE the shell pop up and be held securely by the extractor before it chambers the round. Absolutely safe. For bolt rifles with that silly push-feed, chamber the round, then open the bolt and draw it back, make SURE that the extractor is holding it. Safe then.

Ten thou is not really a lot, but it could be just enough to make a problem. RIMMED cartridges aren't anywhere nearly as much problem: good reason for the whole world to use .303, I would think!

Good luck,friend.

Hope this helps.

Hatcher fired .380 ACP in a 9mm Luger because the extractor held the cartridge against the breech face, and the extra .07 headspace was of no consequence. Of course the .380 didn't have enough power to cycle the pistol.

Pull the bullets, reduce the charge and seat the bullets to just engage the rifling if you can. That'll keep the brass up against the bolt face for the most part- you need good bullet to brass engagement. Otherwise, it's going to pretty much scrap.