I've ran a few boxes of the Federal aluminum cased 9mm through my PPS43c without issue. The cases show no sign of swelling or stress. The brass cased NATO spec ammo is the only cases that showed signs of slight swelling at the base, like the glock "smile". But now I'm reading all these post about not using aluminum cased in blow back weapons as it can blow them up. Can anyone confirm ? Has anyone ran a lot of it through a uzi, AR 9mm or other ? -Thanks

Not sure why Al cased ammo would blow up Al is not exactly a weak metal (it is not steel).  I have been running it for awhile in my Glocks and other 9mm pistol (not direct blow back) only experienced 2 malfunctions in the 2K I have shot and I attribute them to underpowered rounds because the recoil was very light when the malfunction occurred.  I am not an expert on the Al cased ammo but I will venture to say Al is on the same level of strength as brass with edge going to Aluminium being the strong metal.  On top of that I do not think the Al cased ammo is pure Al I believe it is an Al alloy so it would be much stronger than brass.  Brass does have more flex than Al so the reloadability goes to brass.

    Interested in people's experience as I got in some aluminum cased ammo to use in a class where we are using ARs chambered in 9mm.  If I remember I will shoot some through my Uzi to see if they are safe in a blow back gun.

I've shot over 10K of alum. Blazer in my UZI and a lesser amount in me Sig. 226 and my Glock 34 with no problems. It runs good in an MP40 and a MK 760 too.

I've reloaded a several dozen rounds of this stuff for fun in 9mm.  What I've found:

The once fired aluminum "brass" is fragile and rips 10x easier than the worst brass cases I've ever used.

So, it absolutely doesn't have the strength of brass.

By the second or 3rd mild reload, the cases are all self destructing.

I used about 100 rounds of it in my EVO, no issues.