Jeff - For sure use them. Cut your load a grain or two if you're concerned but I doubt this is necessary.

As far as depriming LIVE primers, you can do it with regular sizing dies. The thing to remember working with live primers is:

1. Have all nearby open powder sources covered. (My powder measure is usually right beside my press with the lid off.)
2. Wear eye protection.
3. DEPRIME THEM SLOWLY. Primers are CONTACT sensitive...not crush or compression sensitive. You can squeeze a live primer flat if you do it slowly. Just never hit it. That's when they go boom.

Jeff, don't beat yourself up about this primer mistake. Anyone who hasn't made some sort of error with primers probably hasn't loaded very much. Welcome to the club.

I mistakenly loaded 50 rounds of 270 Winchester with magnum primers. I've discovered this before I put powder in them. What now? Can they be shot? Dump them in a pail of water, then resize? Jeff

Sure. Some powders call for magnum primers, even in 270 cases. look through your loading books and find an appropriate powder/bullet combination (150 gr bullets and H4831 comes to mind) load them up and go shooting. - Dan

CCI 250 Magnum primers are the only primer I've ever used in my 270. I've used both H4350 and H4831, with 150 grain bullets.

No problem Jeff. I use Magnum primers in my .25-06 with H4350 and H4831. If you have already established loads with a standard primer, just load a little lower (.5gr.) and work up just to be safe. No reason to waste the brass or primers.