went to the range over the weekend and one of my buddies gota 300 blackout upper a wile back. we went driving around looking for ammo for it. subsonic ammo was everywhere at all the stores. but we only found one local store with supersonic umc ammo. is this the norm? i get it was designed to be shot supressed and sub sonic but i thought there would be much more super sonic ammo out on the shelves.

My local Walmart always has Remington supers on the shelf

This, Academy does too I believe they both sell them for around $16 a box.

I always see the Barnes 110's when I'm at the store. Of course those aren't exactly target rounds unless you have a crap ton of spare $$. The Hornady 110 v max's are also readily available around most sportsman's stores I've been to. The Nosler 125 ballistic tips should also be around but again those are all gonna be above a 1$ a round in most stores. I would recommend buying in bulk online, with some of the cheaper rounds you can get pretty close to .50 cents a round last I was looking.

No need to drive around looking for them. Order online and you'll get what you want delivered to your door.

Academy stocks both super and subsonic ammo

I'll pile on here.  Academy (around here, and all the other Texas stores I've visited) typically stocks UMC 120 grain OTFB.  This stuff is made by Barnes, with Barnes headstamps and Barnes (sadly not available for the handloader) excellent 120 grain open tip, flat base bullet.  It rocks, and it's pretty affordable, too.  They also (almost always) have Remington 220 grain subs, (in UMC and green/yellow box flavors).  I've spent plenty of time playing with the 120s, and they have been great in both my 8" and 16" uppers.  

Shop around online.  You can often wind up with much better deals than in stores.  I've found some stuff just looking in relation to this thread that make me want to spend a bunch of money - and save while I'm doing it!

That's the same stuff I get at Walmart. The supersonic 120s. IIRC its $16/20rds. Seems to be pretty accurate and clean. Very clean. They always have it, but usually only 100 rounds or so.

Academy often has that stuff for $16 - but on sale for about $14 a box every now and then.  I stock up when I can.

I've seen some folks complain that the 120 grain OTFB is "inconsistent," with frequent failures to fire, but it always turns out that their results are from bolt guns, like the Ruger American...  That makes me wonder what's up with Ruger American rifles that they can't consistently set off Barnes-made ammo.  

Exact opposite of my experience. Subs are always harder to find.

Same here.  I end up buying the supers to shoot and reload the brass.  But thats only when I can find it less than $20-25 a box.  Thankfully I have enough brass now that I can hold off for a while.