Understanding IBU

Hello all,
I made a wheat yesterday based loosely on Boulevard unfiltered wheat. Having talked to the brewmaster he says they use different hops every year and it doesnt really matter what you use as the hops are only bittering hops, no aroma or flavor. He said the important thing was to target 12 IBU. So I went with Magnum and Simcoe as that was what they used a couple years back. The magnum is 13.1 AA and Simcoe is 11.3AA. When I put my recipe in beersmith to get to 12 IBU it called for .125 oz of each added at 60 minutes. So thats what I did but holy cow that was only like 10 pellets of each! So is that correct did I make a 12 IBU beer or do I not understand IBUs and beersmith quite right? It was a 5.5 gallon all grain batch with a starting boil volume of 7.79 gallons.

Wheat beers are often lightly hopped. With high AA% hops, you won't use many. You really didn't need to use two types of hops for bittering here. They might use two because they're brewing more than 5g.

12 IBUs is low and those hops had a fairly high AA% so it is not surprising you needed so little.