Has anyone had troubles with the Accu-Mag magazines feeding? I have a 3.850" mag for my 300 WM and when I take my first shot the second round does not pop up like it should. Are there any other manufactures of 300 WM 3.850" magazines?
Yes. The problem is in the magazine. When I load 3 rounds in it and shoot the first round the recoil will cause the spring follower to tilt nose down and get stuck causing the 2nd and 3rd rounds in the magazine to get jammed nose down. Therefore, I have to drop the magazine from the rifle and bang on it to get the 2nd and 3rd rounds to pop back up to the correct loaded position.
Try opening the feed lips up a bit to see if that relieves some tension. Sometimes this has to be done on aftermarket mags. Also if the mags are brand new try stacking some ammo in them and let them sit that way for a while to losses up the spring.
I’d try the feed lips first and open up the front of them just a bit to where the nose of the Bullet is angled upwards a little more. I have had this problem with a 7 saum and accurat Mag and had to shorten my coal a bit too to keep the cartridge from submarining on me if they were pushed to the pint of contacting the front of the mag.