So i sadly sold my savage 12 because no amount of fighting magazines would solve it. Then i started my 300PRC project and found that if i cycle the bolt at normal for me speeds it would do it too. If i went really fast or very slow it would not.

Long story short its not the magazine at all. its the ejector plunger. Found a topic on snipershide about this. Seemed like a fluke to me but i decided to make my rifle do the jam again. This time i held the bolt HARD so that the jam would stay while i removed the magazine to get a look from the bottom side. Sure enough, the damn case head was sitting directly on the flat side of the ejector pin. Stopping it from dropping down so that it could feed into the chamber. Well hell.

Much like the striker on your house hold door, an angle needs to be present on the ejector plunger so that when the case head comes from the 12 o'clock position to center, it can cause the ejector plunger to go into the bolt head out of the way. Allowing the round to feed.

So about a 45* angle on exactly the firing pin side of the ejector plunger is needed. Mind you i messed up the first one and cause weak ejection. It did not need to be shorter. So the replacement came a couple days ago, and i got around to messing with it today. DONE, feeds flawlessly. Loaded and fed about 80rds now trying to get it to do it again. Feeds great, ejects great.