Kak industries webpage has Mac bolts for 100 dollars. Dont know how long they'll be this low in price. There's an $85 blem bolt too but idk how many of those are available. I've got one it works with Glock and sten mags but the firing pin has a tendency to break and I got maybe 300 rounds through mine before it did that's actually how I saw the bolts on sale cause I was searching for a replacement firing pin. ( My firing pin breaking so soon could've been a one off however. My MAF arms bolt is twice as old and never given me problems)