I was driving by the Mason Michigan exit today after a work appointment and at the last minute I remembered reading that BartZ sells 450BM magazines out of "Not Just Guns" there in Mason. Since it's a couple hours from where I live, I swung in quick to see if they had any in stock. Decent little gun shop, my first time there. I was in luck and they had some in stock. I got a 7 round mag for $35.
Looking forward to giving it a try! Feels sturdy! Any of you guys using the BartZ mags?