Blazer for street carry.
The possible problem of case tension has been mentioned,and I have seen bullets displaced in aluminum Blazer cased .38 Special. I will not rely on Blazer in my revolvers, .38 or, especially, the magnums. I believe the auto cartridges use a cement (asphaltum??) in connection with the taper crimp.
My concern is with ammo that remains in a magazine for weeks at a time. Once the factory coating on the Al cases begins to wear off, or if ANY degree of oxidation sets in, the friction of one case against another is greatly increased. I worry that this could effect functioning. I've shot several thousand rounds of 9mm Blazer Al cased ammo in practice, and it has always worked properly in Glocks, Browning HPs, and a Kahr. I've only fired a few hundred rounds of .45 ACP and .40, though. My practice or match ammo only stays loaded in magazines for a short time. I'm willing to accept this limitation for range use. For personal defense, though, I use factory ammo with brass or nickle plated cases.
Yes, I believe in rotating carry ammo frequently. Sometimes, though, I simply take out the carry magazine, reload with range ammo for training or practice, and then reload with carry ammo. I may go for some time before shooting up the street loads, so I never use Blazer for that purpose.
Best,
Johnny