Have any of ya'll run this type of set up before?

Darn you!  I see a build in my future.

Seriously, lots of 5.56 pistols out there; I don't see any reason why 5.45 wouldn't make a nice pistol/SBR...and now I want one.

I can't imagine that being anything else than a range toy of you could get it to run reliably.

It would like a hot .22 mag at those velocities.

A friend and myself built similar  budget  545 pistols back when 7n6 was dirt cheap. Cheap shooting fun guns, a tad bit loud even with the flash can. The weakpoint is the magazines, I ended up modifying pmags as described here on arfcom. My mags worked flawlessly but ymmv. I have fired roughly 2000 rounds without a single failure what so ever.

I am not sure if the current price of 7n6 is worth building an AR around anymore, but I will keep mine around till the barrel is done,  then reconfigure it from there. It helps that I am a big fan of 7n6 in short barrels (krink et al.).

Not sure of your reasoning for this build so hope this helps.

Right after the 7n6 / pistol issue got (wrongly!) finalized, I mounted a spikes 8" upper to a pistol lower. Its f-ing awesome. the ballistics of 7n6 do SOOOO much better out of a short barrel than 556 does and the package is so freakin handy. Its my favorite useless AR

I think I shoot my 5.45 AR pistol more then I shoot my 3 AK type rifles combined...

Damn, you guys are gonna cost me some money. I currently have an Adams Arms 5.45 that runs pretty well. I stocked up 5.45 when it was around $100 a spam can. Currently have enough to burn out the one barrel. Wasn't planning on continuing that round after I ran out but I think I just might.

Nope, but I wish I had.  Well, I would have preferred a 10.5" for my pinned A2 tastes but it would have gone better with my 16" than a 14.5" pinned.

Here's my 8.25" PDW. It's my home defense gun and normally wears a Huntertown Arms Kestrel 5.56.

Crappy pic, but you get the idea...