Lots of good info in this thread. I have (2) tikka 223a and love them. I have several 4 and 6rd mags and while they feed nice when they feed, it sure sucks when the gun goes click because the bolt rode over the room of the next round. I’ve played around stretching the springs and bending them with some trial and error error. And they are now “ok” but not fool proof. I went to a chassis on one rifle and run MDT Poly mags with no trouble now.