Mag issue on Blackout

I built a 300 Blackout on a Stevens 200 and it shoots like a dream. The problem is with the magazine. I've got a blind mag in a Boyd's stock and the .223 follower spring doesn't have enough poop to hold the bullet noses up with much over 140 grains. Racking the bolt just jams the nose into the front of the mag or the receiver below the ramp. Is the spring out of a .308 mag longer and have more tension? I failed to mention it is a centerfire action and these followers are pretty cheap. Any suggestions are greatly appreciated.

Try bending the feed lips open a little at the front of the mag to help the bullet angle towards the chamber better.


Sent from my iPhone using Tapatalk