Model 12 won't feed last shot in mag

I have a mod 12 in .223, and it is a great shooter until the last shot in the mag. It just won't chamber it. Anyone else have this problem? Otherwise it's a fine shooting gun.
Bob

I've had to tweek the feed lips on the internal box mag to get all rounds to feed in my M10 .223, may be yours need tweeking too. Mine needed to go closer together IIRC, and rounds were popping out between the lips, also IIRC.

Sounds like you need to tweek the follower spring a little. If it's just the last shot stretch it a little.

Bob, Just noticed today my 12 does the same thing. If I only put 1 rnd. in the mag. the bolt won't pick it up but if I put 2 in it will. If I put a little pressure down on the bullet nose and run the bolt it works. I think the second rnd. in the box levels the case and makes rise in the rear. It looks like the rear of the box needs to be raised up a little. Is there a way to do it? Does the box in the stock just pull out or is there a trick to remove it? Dave

Stretch the spring under the follower a touch.