Quoted:
How dirty/bad is it? The gun shop sages say it's so dirty it will scratch up your bore.
Poll incoming.
Gun shop sages are usually morons...especially the ones that lounge there and offer unsolicited advice.
At this point I've put a few thousand rounds of Blazer brass and aluminum cased ammo downrange in 9mm and .45 ACP without much problem. The aluminum stuff actually shot considerably cleaner than WWB, and was more reliable than WWB. The brass cased ammo is pretty clean as well, certainly much cleaner than Remington's bulk ammo or WWB. Most of my handgun ammo stash at the moment is Blazer of some type or another. I'm not concerned about it.
I prefer brass cased, but the aluminum cased stuff works just fine even in my 1911s. The only downside to the aluminum cased stuff is that it's not as robust as the brass cased ammo. The case can be pierced more easily than brass cased ammo and it doesn't stand up to repeatedly being cycled as well as brass cased ammo...but there has to be some tradeoff, right?
Accuracy is decent. At the Vickers 1911 class this month I didn't notice any real accuracy issues caused by the ammo, not even back to 110 yards.
EDIT –– And "scratch up your bore"....
Yeah. I'm sure that a couple of flecks of unburned gunpowder is going to be a big deal for a metal tube that has a hunk of brass coated lead zipping through it at high speed.