I have shot the aluminum Blazer for yrs, usually in lost brass matches, ( that means when the case hits the ground, it belongs to the range ). The reason to do that is time, it prevents that 2-3 minutes per shooter per stage, to police brass. If you have 350-400 shooters like we do at the Glock match, that makes a big difference. Now is aluminum weaker than brass blazer, I would say yes and no, aluminum does not flow like brass in a chamber, Grouch since you only had trouble in the lever guns, sounds like the ramp portion of your barrel is too much for the aluminum to keep contained, in a revolver, the case would be completely supported. As to hang fires, I have not witnessed this in Blazer, and agreed, is a dangerous situation. As to failures to fire, I have seen a lot of this in the Glock matches, reason, cci primers are the hardest in the business, as much as I love Glocks, they have a lighter primer hit than a lot of other pistols. I had a case of Israel 9mm carbine ammo, said on the box, not for use in handguns, the stuff was loaded hot, and I would only get 50% of the ammo to go off in my M17, even after loading them again and taking 4-5 attempts. I kept all the unfired ammo home, next outing, I brought my 9mm 1911 and my CZ75, no ftf's, even on the stuff that had not gone off initially. Our ex Glock rep, John McNally had cases and cases of the aluminum stuff, and that is all he shot.
I have friend who reloads aluminum blazer, how can he do that with a Berdan primer, he uses Lee sizing die with the unbreakable decapping pin, and punches a 3rd flash hole in it, he only shoots this stuff in his Mac10, and blazer brass is free everywhere.