Heres some pics of some 30 rounders i had lying around. I sandblasted them, then sprayed them with Black Krylon.
What do you guys think?
Before:
https://www.m4carbine.net/attachment.php?attachmentid=2082&stc=1&d=1236710949
Sandblasted:
https://www.m4carbine.net/attachment.php?attachmentid=2083&stc=1&d=1236711003
Painted:
https://www.m4carbine.net/attachment.php?attachmentid=2084&stc=1&d=1236711142
looks like the krylon touch.
Wouldn’t sandblasting destroy the anodizing?
I’d have just piss coated them without the blasting… Actually, I wouldn’t have even gone to that much trouble.
Hmmm, old Centers?
Any particular reason you did black?
I use PermaSlik to refinish my old USGI mags. But they have to look a whole lot worse than yours before I even consider it. And I’d never sandblast them…but if you’re happy with them, that’s all that really matters.
I agree with MarkM, why go through all that effort. The mags are just going to get beat up again anyways. Mags are disposable, who cares what they look like run em til the feed lips break off.
-DM-
The sandblasting gave them a more rough texture, in my opinion, a better grip. Besides, I had some time on my hands and nothing better to do. The choice of black was because thats all i had on hand. They suit me just fine. 
Looks good!