Yeah, when I chronoed it out of mine it made 1350ish. The 1250 test number given is out of a 4" barrel.
Regardless, with this ammo on offer, we have to draw either of two conclusions.
1) A major ammo manufacturer is selling ammo that will blow up your gun.
2) This stuff isn't so dangerous that it can't be talked about around impressionable new shooters.
I wouldn't run range brass in major through an unsupported chamber, but 9Major isn't a WMD.