Initially I had a Leupold 3-9x40mm on it and had to remove the rear sight. I could get about 3 thicknesses of paper between the scope and the barrel and the hammer was a bit crowded. I did eventually (last year actually) upgraded to a different scope.
Currently I have a Bushnell Elite 4200 1.5-4x24 (30mm with illuminated reticle) on it and this scope seems high even in the low rings I have it in. Not an excessive amount of clearance for the hammer with any scope design, since the rear housings are pretty well within the same diameter range. Optics are always a matter of personal preference, once you choose the right specifications for your hunting location, and your Bushnell sounds very nice indeed. In our bush country here in Central Ontario the 16x would be of little use, but 2.5 to 4 power I consider ideal for the kind of opportunities we have here. Yours sounds like it will be ideal in a wide range of hunting situations (i.e. distances). The 42mm front objective is as big as one can go with the BLR in low mounts in my experience.
Is your Bushnell illuminated?