nfldraftdog wrote:Humm......how can the SIG 556 magazines work on a Bushmaster 450? The rounds are such a different size, the feed lips would be to small wouldn't they?
The 5 round 450b mags that Bushmaster sells are just straight 20 rounds 223/5.56 magazines with a "Sled" follower like you can buy at Fulton Armory.
The Follower is normally used by highpower and DCM shooters for single shot loading.
So the feed lips are just 223/5.56 feed lips. People have tried using standard 30 mags with varying degrees of succes, but most people have had good luck with the sig 556 mags.