You'd have to be incredibly stupid to inquire about an ammo type that is only fired by prohibited weapons on an online forum.... Great way to have a knock on your door.
There are companies in the states making 5.45 AR-15 barrels, so any of our 180 derivatives or straight pulls can use them. I've also seen one custom ACR states side that has been done.
There's also a few East German SSG 82's here but it would be a sin to shoot corrosive surplus through those.
I had a gunsmith who had his own small firearms company thing he ran he always tinkered had a few projects he even sent to the lab to have classifications done. But as far as factory offering of 5.45x39 I can’t think of any but I have seen a few like savage bolt rifles rechambered in 5.45x39 for fun and to test the rounds and such by gun enthusiasts here in Canada. I think he went the hard way for his, custom barrel he made from a blank and new bolt face and the like so there are definitely a few rifles in 5.45 but not much
I think their more unicorn projects like the guys who rechambered an sks to 5.56 and to use ar mags
I have some 5.45x39
Am i now also an assumed criminal? Yall are ####ing goofballs